Bug 425227 - Orion Editor Content Assist Improvements
- Improved filtering performance by no longer calling computeProposals() for every model modification but rather making contentAssist.js filter the proposals itself if possible.
- Moved non emphasised proposals to the bottom of the list
- Simplified content assist deactivation rules
- Added separators between proposals from different providers
- Styled keywords as non-emphasised and added "Keywords" title
- Ensured that separators aren't highlighted when hovered with mouse
- Added HTML comment proposal (<!-- -->) to htmlContentAssist.js plugin

--Signed-off-by: Elijah El-Haddad <elijahe@ca.ibm.com>
Bug 377525 - Automatically trigger content assist
- Added automatic content assist triggering support
- Automatically triggering HTML content assist when '<' is enterred by user
- Automatically triggering JavaScript content assist when '.' is enterred by user

--Signed-off-by: Elijah El-Haddad <elijahe@ca.ibm.com>