Flag lib32 package out of date when corresponding non lib32 pkg is marked out of date

[jelly]

For example when glibc is flagged out of date, flag lib32-glibc out of date as well.

[jelly]

The code looks quite simple to change but has been specifically written to support one pkgbase in packages/view/flag.py. This needs to be extended to support multiple packages with some re-use of code.

[fish-dango]

Hello! I can try to finish the fix in this pull request.

#230

[jelly]

@fish-dango feel free, there where some issues with the PR which requires additional testing and fixing.