GitLab

Examples: now builds CWrappers as a library; modified C builds to use it; added visual studio project to build Argon example in Fortran.
System.h: addForce() wasn't returning the index.

Fixed getTime() calls in _openMMBrookInterface()
Based on Sherm's suggestions:
changed '#ifdef WIN32' to '#ifdef WIN32 _MSC_VER;
reordered include files so that system files after OpenMM files
all include files should be C++ files now (as opposed to C files (<math.h> -> <cmath>

Checkpoint: added HarmonicBond, HarmonicAngle, and PeriodicTorsion to C Wrappers so these can be accessed from the Fortran Module per Mark Williamson's request for Amber.

- MingW, where "WIN32" is set by CMake but the compiler is not Microsoft's (should use _MSC_VER) in that case, and 
- in gcc 4.4 which is fussy about some issues that earlier versions were silent about, such as passing a string constant to a "char*" rather than a "const char*".
I also fixed a syntax error in CMakeLists that showed up in the OpenMM workshop for some unknown reason.

Brook is not currently building correctly; I think it has not yet been fully converted to the getTime() interface needed for variable step integrators.

Added FCPPLIBS variable in makefile to accommodate systems where the fortran compiler needs some extra libraries to link with C++. Also added a Makefile.mac with a possible good library combo.