Fix filename in core_gyp_generator.pro's makefile on Windows

Do not add version to end of filename by
Qt5/mkspecs/features/resolve_target.prf, otherwise nmake install
won't find it.
Other projects already have skip_target_version_ext in they CONFIG.
None of the Qt libraries has version in they filename on Windows.

Change-Id: Ifc56a12b9312e7cefe26f5d19e1d1769e73298f6
Reviewed-by: Andras Becsi <andras.becsi@digia.com>
Add project's directory to includepath on Windows

Unlike other OSes, project's directory is not included by default to
includepath on Windows. This would cause missing file errors while
building.

Change-Id: I64b83e13adaae1ee1730caebcf7442973b573c3b
Reviewed-by: Andras Becsi <andras.becsi@digia.com>