Improve `git log -L` functionality

Hi.
 I want to `Trace the evolution of the line range`. 
And not committed change is sort of evolution and should be taken into account by -L option. 

Currently I MUST `stash save` change, look actual line number, trace evolution, `stash pop` to bring back current change.

EXPECTED: Allow to use those line numbers which I see in my editor without excess `stash save/stash pop` commands

If file has not committed change then this change maybe shown by `-L` as commit NOT COMMITTED YET If file staged 'commit STAGED'

More description what is comming on: https://stackoverflow.com/q/49130112/4632019