* Support CRLF when splitting code lines for display
* refactor, fix mixed match
* fmt
* split on both LF and CRLF, use raw literals in regexes
* simplify
Tests indicate that line length alone does not make browsers slow, so
increase the default threshold after which diffs get surpressed for line
length from 500 to a more reasonable 5000 characters.
Fixes: https://github.com/go-gitea/gitea/issues/1826