fix for static builds with mingw-w64 compilers

[BMBurstein]

Fix for issue #132

[eXpl0it3r]

Would be nice if the patch gets applied, otherwise one always needs to hack the macros to get it working...

Additionally it could also get prevented/fixed by correctly linking the dependencies.

[LaurentGomila]

There's no point fixing this if there's no 64-bit version of the external dependencies.

[eXpl0it3r]

The MinGW-w64 project doesn't provide only a 64bit compiler, but they also provide a 32bit compiler, which has the same problem (e.g. see my Nightly Builds).
For the 32bit MinGW-w64 branch I'd have to change the path to ${STANDARD_LIBS_PATH}/i686-w64-mingw32/lib/lib${lib}.a.

[LaurentGomila]

I see.

[eXpl0it3r]

I've just tested this pull request and it works for all the tested compilers and see no reason for it not to work on possibly others.
I've tested the following compilers:

• Official MinGW32, just to see that nothing breaks.
• Visual Studio 2010, just to see that nothing breaks.
• MinGW-w64 x86 compiler by rubenvb
• MinGW-w64 x64 compiler by rubenvb
• MinGW-w64 x64 TDM

Would be nice, if this could finally get integrated!

[LaurentGomila]

Thanks for testing it!

I merge the modifications, but the 64-bit dependencies are still missing ;)