Use properties file to map file extensions to CM3 mime types

Use a properties file to map file extensions to the mime types
used for syntax highlighting in codemirror.

Using a properties file makes it easier to update the mapping
and keep the lines sorted.

Change-Id: Ic84c01b5fd783ffbc59873daa5e758317409f163
(cherry picked from commit bac7d1c053c8a5cdcf84c9628e29650df9fa5df2)
2 files changed