mfs: depgenmodule: Change API of rpmfcGenerateDepends()
mfs: depgenmodule: Add mfsPackageGenrateDepends() to MFS
mfs: depgenmodule: Add depgenmodule
Add support for disabling MFS and blacklisting modules via regexp

Wheather MFS should be enabled or disabled is controlled by a macro:
%{_rpmbuild_modules_enabled}

Which modules are blacklisted is controlled by a macro:
%{_rpmbuild_modules_blacklist_regex}

This patch also adds these functions:
getRegerror()
mfsCompileRegEx()
mfs: Move MFS initialization to rpmSpecBuild()
mfs: Add support for _rpmbuild_modules_directory macro that can be used to specify a directory with modules.
mfs: Add mfsManagerSetCleanupFunc(), mfsManagerGetGlobalData() and prototype for MfsModuleCleanupFunc()
mfs: Add documentation into mfs.h
mfs: MfsFileLines, MfsFileFiles and MfsPolicies lists now return const string.
mfs: Update langsubpackagesmodule
mfs: Remove useless const qualifications
mfs: Remove unused variable