Handle long lines

For lines longer than 500 characters:
- Split line per match (and per 500 chars as window length) and do all the following steps for each:
  - Print line number (if not disabled)
  - Take some characters before and after the match (keeping a 500 char window length) as context
  - Add `...` before the match if it is not within the first characters of the line
  - Strip colors if option given
  - Print individual match
  - Move the window

Before and after screenshots:
https://cloudup.com/cM9D7mBIsyp