Improved search feature.
Removed useless public search methods
Upgraded CodeMirror library rom 3.14.0 to 3.21.0
Changed ocaml to mmlike mode since it has changed in new version of CodeMirror.
Removed custom match highlighter and used CodeMirror's one
Sorted alphabetically js script tags
Created a copy of match-higlighter that handles case insensitivity
Addressed feedback
Merge pull request #207 from beaufortfrancois/improvedSearchFeature

Added buttons to switch to previous/next search match. Show the number of found matches and the index of the current match. Highlight all the shown matches.