Added Find Next and Previous buttons
Fixed typos
Remove RTF from the list of supported formats.

Close #202
Fixed case insensitivity
Fixed early feedback
Addressed findNext  feedback
Improved focused event handler
Replaced codemirror onFocus by body focusIn listener
Clean event listener
Make sure suggested name when saving a file has always an extension
Fixed comment
Merge remote-tracking branch 'upstream/master' into addTxtExtension
Forgot semi-colon
Addressed last nits
Merge pull request #203 from beaufortfrancois/addFindFeature

Add basic find previous/next feature
Merge pull request #205 from beaufortfrancois/addTxtExtension

Added txt extension to suggest name when saving it.
Added basic search overlay