add isBinary to language def
enable file extensions for binary file types
 review comments:
- factor dupe code into function
- also handle file names for binary files
- do not register binary flagged lang as pending
- added defineLanguage() docs for isBinary flag
- remove comment in wrong place.
- Spell CodeMirror in camel case
Merge pull request #5957 from adobe/couzteau/fix-5749-LM-mode-warning

Couzteau/fix 5749 language manger mode warning on binary file