wxmp3gain-4.0-bp160.1.12

- Replace wxWidgets-3_0-devel for wxWidgets-devel BuildRequires:
  Package builds just fine with the newer 3.2 version.

- Use %autosetup macro. Allows to eliminate the usage of deprecated
  %patchN

- Do not recommend lang package

- Update to version 4.0
  * Bug fix for unicode filenames
  * Added Turkish translation
  * Added Croatian translation
  * Code refactor in make/build process
- Switched build to cmake
- Dropped wxmp3gain-makefile.patch
- Added wxmp3gain-docs.patch

- Initial package (v. 3.7)