Feature function objects

Lots of updates migrated from internal development line

### Updated functionObjectFile
Old code maintained a list of file pointers, and provided a clunky interface to output to file.  Although OK for function objects that only created a single file, those that created multiple files were required to refer to each by an index and making it very easy to introduce errors.
The new code simplifies the functionObjectFile class so that it provides helper functions to create and write to files, and no longer maintains a list of file pointers.  Instead, each function object must create and take responsibility for all of the file streams that it requires.
Changes propagated across dependencies:
* fieldValues
* forces/forceCoeffs
* yPlus
* fieldMinMax
* residuals
* regionSizeDistribution
* fieldMinMax
* cloudInfo

### Created new functionObjectState
Previously, if function objects required to store data on disk to enable smooth restarts, e.g. fieldAverage, the object would need to provide the mechanism for reading/writing state information itself.  This class abstracts out the reading/writing of state information in a straightforward manner, whereby an object can retrieve its own data, or retrieve e.g. the latest available data from another object (e.g. see fieldValueDelta).
* fieldAverage
* fieldMinMax
* forces
* forceCoeffs

### Created new runTimePostProcessing function object
New function object to generate images at run-time, or in 'post-processing' mode via the execFlowFunctionObjects utility
* Constant DataEntry - added construct from components
* Set and surface writers updated to enable retrieval of filename of generated output
* Additional changes to surface writers from internal line:
  + Ensight collate times option
  + Nastran output updated based on user feedback
  + new boundaryData output


See merge request !5

Merge branch 'feature-functionObjects' of develop.openfoam.com:Development/OpenFOAM-dev-OpenCFD into feature-functionObjects

- Allows generation of images (currently PNG files) during the run
- ... or afterwards by invoking the execFlowFunctionObjects utility
- Wrapper around VTK functionality
- Support for objects:
  - text
  - points (glyphs: sphere, arrow)
  - lines (tubes)
  - surfaces (wireframe, shaded, combination)
- Colour using:
  - user-defined
  - field values (several colour maps availale)
- For image sequences:
  - dynamic views (camera movement)
  - objects can appear/disappear using opacity
- Building
  - VTK dependency v6+
  - satisfied using ParaView from ThirdParty directory
  - or separate VTK installation

- New boundaryData surface writer
- Moved templated code into separate files
- Output filenames written to functionObjectState dictionary
- Ensight surface writer now supports a 'collate times' option [mattijs]
- Nastran surface writer updated based on user feedback

Properties stored in state dictionary:
- Moment coefficient: Cm
- Drag coefficient: Cd
- Lift coefficient: Cl
- Front lift coefficient: Cl(f)
- Rear lift coefficient: Cl(r)

Properties stored in state dictionary:
- normalForce
- tangentialForce
- porousForce
- normalMoment
- tangentialMoment
- porousMoment

Properties stored in state dictionary:
- minimum value: min<identifier>
- position of minimum value: min<identifier>_position
- processor ID of minimum value: min<identifier>_processor
- maximum value: max<identifier>
- position of maximum value: max<identifier>_position
- processor ID of maximum value: max<identifier>_processor

Also
- added documentation to header
- added 'resultName' to enable user to specify alternative name for
  output field

Also added 'resultName' to enable user to specify alternative name for
output field

Also added output of diameter info, D10, D32 and DMax

Note: added as a pointer since the list operates in multiple modes, e.g.
as constructed by the Time database and 'outside' by
execFlowFunctionObjects

Class now provides helper functions to generate files on-the-fly by
function objects, as opposed to attempting to control all files needed
by the function object (earlier implementation lead to over-complication
and was error prone)

This new class provides function objects with a database (dictionary)
to store current state information to enable smooth restart behaviour.
Additionally, current results can be stored so that they can be accessed
between different objects.

- Allows generation of images (currently PNG files) during the run
- ... or afterwards by invoking the execFlowFunctionObjects utility
- Wrapper around VTK functionality
- Support for objects:
  - text
  - points (glyphs: sphere, arrow)
  - lines (tubes)
  - surfaces (wireframe, shaded, combination)
- Colour using:
  - user-defined
  - field values (several colour maps availale)
- For image sequences:
  - dynamic views (camera movement)
  - objects can appear/disappear using opacity
- Building
  - VTK dependency v6+
  - satisfied using ParaView from ThirdParty directory
  - or separate VTK installation

- New boundaryData surface writer
- Moved templated code into separate files
- Output filenames written to functionObjectState dictionary
- Ensight surface writer now supports a 'collate times' option [mattijs]
- Nastran surface writer updated based on user feedback