This commit fixes four issues:
* Instead of WRITE,APPEND, resource.rc was generated using
WRITE,WRITE, which erased #include <windows.h> and prevented
any symbolic definitions (like RT_MANIFEST) from working.
This silently included them using a string type instead,
which did nothing.
* WINVER is bumped to Win7, since that's what we target now.
* Index of RT_MANIFEST is changed to 2, since that's what
it has to be when ISOLATION_AWARE_ENABLED is defined.
* Platform is not restricted to X86 in manifest, since there
is no point in doing so.
whitequark