ContentSearch: Show error notification unless `res.stdOut`.
Add basic search infos
Build correct grep command
Adapt formatOutput for search with grep
Add searchtypes.coffee to files to load
Add flags -A and -B on grep command

Add comments on all grep flags
Use editor settings data instead of searchtypes.coffee
Parse correctly new format from grep (with -A and -B)
Fix isCAseSensitive and isWholeWord
Fix extensions listing for grep command
Merge pull request #9 from SamyPesse/feature/removeag

Use grep instead of ag for searching code.