Merge pull request #17 from jgmdev/premake

Added os.sizeof to premake.
Merge pull request #18 from jgmdev/premake

Small heading change to premake.
Merge pull request #19 from jgmdev/premake

More methods in wx.setup.header and support for #  define.
Some corrections for wxBase project script, drafts for wxQA and wxCore.
Moved setup files.
Updated configurations.
Fixed typos.
Added a temporary test (wxUSE_LIBMSPACK).
Minor corrections to lib scripts.