etc/bashrc, etc/config.sh: Updates provided by Bruno Santos:

 1. "foamCompiler" was changed to a more permanent "WM_COMPILER_TYPE"
    environment variable, so that it can be used by 3rd party
    installation scripts, such as "makeGcc", "makeLLVM" and so on. More
    on this will be provided in issue #1215.

 2. The script functions such as "_foamSource()" and "_foamAddPath()"
    were moved to a new file "etc/config.sh/functions". It has the
    ability to set or unset, depending on whether "WM_BASH_FUNCTIONS" is
    defined or not. This allows for these functions to be reused by
    other scripts, such as "makeGcc".

 3. The script "etc/config.sh/CGAL" relies on whether a local
    environment variable "SOURCE_CGAL_VERSIONS_ONLY" is defined or not,
    so that it will load only the version settings if it's defined. This
    is to make it easier to call this script from "makeCGAL". Although
    it still feels a bit of a clunky hack, but I didn't manage to deduce
    any other way we could do this :( I didn't add indentation within
    the if-block, to make it easier to read the changes. In addition,
    the local variable "common_path" is used to shorten the length of
    the lines and use slightly less repeated code.

 4. Added another new script "etc/config.sh/compiler", which has only
    the version numbers for the compilers taken out from the "settings"
    file. It currently depends on "WM_COMPILER_TYPE" for setting the
    variables, the same way it did with "foamCompiler". This script is
    now always sourced from the "settings" file, for the following
    reasons:

   - "makeGCC" and "makeLLVM" can now take advantage of this script file.

   - The example "compiler" script (detailed next) can rely on this
     script file and then override parameters on-demand, as well as
     allowing for system compilers to have dedicated settings, such as
     setting "WM_CC". This is similar to how the example environment
     script for "paraview" works.

 5. To the script "etc/config.sh/example/compiler" were added a few more examples:

   - It now starts with a block where it first loads the default "compiler" script.

   - Has a "WM_COMPILER=Gcc48u" case example for when we try to use GCC
     4.8 in Ubuntu 15.10. This is just to give the idea that in a
     particular system, we might have several system-wide compiler
     versions. For example, in Ubuntu 15.10, there is GCC 4.7, 4.8 and
     5.2, which could be used for testing performances or compatibility
     with some other 3rd party library.

   - Has the "WM_COMPILER=Icc" case example, related to the original bug
     report, where "WM_CC=icc" and "WM_CXX=icpc", so that the user then
     simply copies this file to their own local preferences folder.

 6. Small bug fix in "etc/config.sh/mpi", where unsetting "minBufferSize" was missing at the end of the script.

 7. Small change in "etc/config.sh/paraview", where "CMAKE_ROOT" is set
    along with "CMAKE_HOME". This is due to a rare issue that occurs on
    people's systems where they have a custom system-wide CMake version
    installed and which is used by having "CMAKE_ROOT" set on that
    environment. This can mess up OpenFOAM's custom ParaView builds,
    given that conflicting CMake versions can lead to not building
    ParaView at all.

   - For more details about "CMAKE_ROOT":
     https://cmake.org/Wiki/CMake_Useful_Variables [^]

 8. The scripts "_foamAddPath _foamAddLib _foamAddMan" were not being
    unset at the end of "settings". They are now unset at the end of
    "bashrc", through a call to the new double-use "functions" script.

Additionally all references to "foamCompiler" have been changed to
"WM_COMPILER_TYPE".

See also http://www.openfoam.org/mantisbt/view.php?id=1232