WIP: Add keywords search mode
Merge pull request #101 from tbabej/master

WIP: Add keywords search mode (keyword-search branch)
Merge branch 'keyword-search' of https://github.com/dvorka/hstr into keyword-search
TABs > SPACEs
Adding highlighting of keywords matching lines.
Adding yellow highlighting of matching patterns for all C-e modes.
TABs > SPACEs
Proposing improvements in keywords match when the page is not full.