Remove Module::Build::YAML

It will be offered on CPAN in a different dist in case anyone is really
depending on it
Remove Module::Build::ModuleInfo

It will be offered on CPAN in a different dist in case anyone is really
depending on it
Remove Module::Build::Version

It will be offered on CPAN in a different dist in case anyone is really
depending on it
Get rid of "use vars"
Added use warnings to all modules

Only Module::Build::Base had it previously
Prepare for release 0.4207