- lazier evaluation of project name and version based on the directory
  name. Avoids heuristics based on directory names unless really needed.

- cope with alternative directory locations.
  For example, OpenFOAM+VERSION etc.

The combination of the two above appears to be sufficient to open up
the directory naming possibilities.

- additional -list-test option (tests for existence of directory).

- cleanup variables last in etc/bashrc for a clean exit code

- this allows the sys-admin to provide base values independent of any
  WM_PROJECT_SITE value.

- support names like openfoam-<VERSION> (eg, what spack uses).
- robustness improvements

- this corresponds to what various module or build systems provide.
  ThirdParty builds are unaffected since they install into FOAM_EXT_LIBBIN

- the regex was not being unset on assignment.
- drop unused recompile() method as being dubious

- this makes it possible to perform additional operations
  on surface values that have been previously sampled.

- support vectorField for weighting operations.

- reduce overhead by avoiding creation of weight fields, Sf fields
  and combined surface geometries unless they are actually required.

- extend some similar concepts and operations to volFieldValue

Fixes #416

Closes #416

See merge request !96

This scalar allows to introduce a factor for cloudy sky between 0 (clear) and 1 (fully cloudy)

- makes it easier to identify at a later stage

- handle sourcing bashrc with a relative path (issue #383)
- handle sourcing from bash and zsh.
  Still need manual intervention when sourcing dash, sh, or ksh.
- replace grep in etc/cshrc with sed only
- logical instead of physical path for WM_PROJECT_DIR (issue #431).
  Doesn't seem to be possible for csh/tcsh.

  * Continue using physical locations when comparing directories,
    but not for the top-level FOAM_INST_DIR, WM_PROJECT_DIR.

- relocate WM_CC, WM_CXX overrides from etc/config.*/compiler
  to etc/config.*/settings to ensure that they are left untouched
  when etc/config.sh/compiler is sourced while making third-party
  packages (eg, gcc, llvm, CGAL).

- provide fallback FOAM_TUTORIALS setting in RunFunctions

STYLE: remove "~OpenFOAM" fallback as being too rare, non-obvious

- ignore top-level /build and /platforms directories

- minor cleanup of wmake sources

ENH: Function objects - updated logic to determine whether or not to instantiate a time-based function object.  Fixes #439