No Commit Required Tagger

[ashcrow]

Wishlist: Add a tagger that doesn't require a commit.

[dgoodwin]

Today when we commit on tags we are comitting:

• metadata file in .tito/packages/pkgname. This just contains the last tagged version for the branch, and the sub-directory to the package. (Note: we support repos with multiple packages in them, those packages can move around)
• Version or Release in spec file
• Changelog in spec file

If we start looking at Dockerfile builds the last two are of no concern anymore, but we'll need to know a version for when we tag the image.

For the metadata, we could probably get a little more presumptive and assume where you run tito is the location you're building a sub-package from, assume a package name from directory or a config file. For the version as mentioned in other issue, I think we could scan the git tags in order looking for the last one that matches.

Then tito tag just becomes creating a git tag for the most recent branch HEAD.

[FrostyX]

Related or possibly a duplicate #441