Simple pagination added to git log pane

[gcarvalho]

The wait time for the git log command has been bugging me, mainly since 90% of the time I just want to look at the last few commits. I changed it to load a set number (currently 10, from a constant in the module) with a n+1 row stating "Continue". Choosing that row will simply run git log from the last hash for the same number of rows, and re-load the panel. It could be improved (confs to turn on/off, and for number of rows), but first I wanted to check wether you'd be interested.

[kemayo]

This is something I'm interested in, yes. Go ahead and polish it up and add the relevant config settings, and we can get it merged.