JIRA issue: CORE-17684
- Add HEAP_strdupA2W_buf and HEAP_strdupA2W_buf_free
  helper functions for quick string conversion.
- Optimize HEAP_... functions.
- Add IntConvertFontPaths helper function.
- Support multiple files in AddFontResource function.
- Add cFiles parameter to some internal font addition/
  removal functions.
- Half-implement NtGdiRemoveFontResourceW and
  RemoveFontResourceExW functions.