Add ability to change the name of SWIG MapScript modules to the build process.

[sdlime]

Sometimes it's necessary to run multiple versions of MapScript on the same box. At least for Perl-MapScript that involves editing a couple of files before generating the interface. From that README:

If you need to change the name of the mapscript module (default=mapscript) you need to:

  1) edit ../mapscript.i and change the name of the swig module
  2) edit Makefile.PL and edit the name 'mapscript' in the WriteMakefile subroutine call
  3) edit plmodule.i and change the name 'mapscript' to whatever the new name
     will be throughout the file

and now build as normal.

It's hard (impossible?) to make these changes with the current cmake process.

--Steve

[geographika]

Would it be possible to set a command line variable and pass this to SWIG?

SWIG interface files must begin with a %module declaration—for example, %module module-name, where module-name is the name of the target language extension module. If the target language is Ruby, this is akin to creating a Ruby module. It is possible to override the module name by providing the command-line option –module module-name-modified: In this case, the target language module name is (you guessed it) module-name-modified.

https://www.ibm.com/developerworks/aix/library/au-swig/index.html

I'm running into a related issue with the PHPNG module name somehow causing the Python mapscript module to rebuild with each make call.