Multiple fixes, features related to hg-log and dark-mode colors.

[juszczakn]

Adds date column similarly to #46 as well as multiple other features.

• Added date column
• Added author column
• "killall-monky-buffers" feature to quickly close all related buffers
• Adds 'log-current-branch' and 'log-all-branches' feature

@lbolla take a look at this, see if it works for you.

[lbolla]

Thanks!