Add version sort support

[wader]

No description provided.

[v1gnesh]

What could help with this is if the dates were taken into account too (if necessary).
As you said, having a char sometimes means pre-release or alpha or whatever.

1.5.6a1
1.5.6a2
1.5.6a3
1.5.6

And it means the opposite with

1.4.5
1.4.5p1
1.4.5p2
1.4.5p3

For fetch: at least, dates are usually available in the same page as the version listings.
Not 100% sure about gitrefs.. likely to be available though.

[wader]

Good points, hmm for git i think you probably have to digg into commit blobs etc to see dates, not sure i would like to do that.

As you said about pre-release/patch-release, version sort would probably also need to kind of both constraint like semver and config how to interpret some columns. Tricky, will have to think about this a bit.