[PATCH 0/3] gitk: show latest change to region

Hi!

I quite like the "Show origin of this line" feature of the gitk. It is more convenient than blame, because it directly answers the question which is usually addressed to blame.

But, sometimes there is no "key" line which one could blame. Instead there is a function, block, or some other region of code. So I need a similar feature, but for several lines rather than for a single one.

The series of patches implements the feature. It consists of 3 patches:

* gitk: refactor: separate generic hunk parsing out of find_hunk_blamespecs{}
* gitk: refactor: separate io from logic in the searching origin of line
* gitk: pick selection for region blame

It also requires the "gitk: use single blamestuff for all show_line_source{} calls" patch, which it replies to.