Replace whitelist / blacklist with SearchEngine

[BerndNK]

With the much more flexible SearchEngine in place, the definition/branch black/whitelists became outdated.

The whitelist as well is a little used feature.

Therefore I'd suggest to just have a blacklist, with the same capabilities as the default search function.

Based on #140 & #52

Edit:
Whitelist is still necessary as a search cannot be inverted (yet)

[TheSylence]

The whitelist as well is a little used feature.

:o
I use this to see every branch my team has, including the ones I did not commit on.

Maybe we could add something like "saved searches"?

[BerndNK]

Well true, there is no way to invert a search (yet).
So black and whitelist it is then.

Saved searches is already a planned feature in form of a history. Although not a "pin this search" feature.

For teams I'd also suggest #165