Do not set display line number for invalid lines
Merge pull request #6442 from busykai/fix-6441

Fix #6441.
- added a testcase for https://github.com/adobe/brackets/issues/6441
Merge pull request #6495 from adobe/jasonsanjose/issue-6483

Maintain folder expanded state when last child is deleted
Merge pull request #6522 from adobe/jasonsanjose/issue-6474

Prevent duplicate tree nodes when renaming the only file in a directory
clean up
Escape html-sensitive characters for any file/folder without the extension.
Merge pull request #6478 from adobe/pflynn/find-highlighting-tweaks

Fix several visual issues with find result highlighting:
Merge pull request #6534 from adobe/dangoor/quickview-pref

Changes QuickView over to the new preferences system
Merge pull request #6529 from ishanatmuz/followupFor#6348

find in files stays in a single line
- added another linter that returns a string for the line number
comment out use of defaultExtension pref to avoid problems with ScopeManager
Merge remote-tracking branch 'origin/master' into bchin/disable-defaultExtension-pref
Fix bug #6542 (Exception thrown on save if file not visible in project
tree) - move initialization of wasOpen after the check that early-exists
when $directoryNode is null.
Merge pull request #6545 from adobe/pflynn/fix-tree-npe

Fix bug #6542 (Exception thrown on save if file not visible in project tree)
Merge pull request #6543 from adobe/bchin/disable-defaultExtension-pref

disable defaultExtension pref, for issue #6539
Wait for unwatch (and index clearing) to finish before getting the new project root - for #6540
Fix for #6541 that leaves preferences in place after conversion.

When you switch to Brackets 36, preferences will be converted automatically.
If you switch back to an earlier Brackets, your old preferences will still
be there. Any changes you make in that earlier Brackets will not be re-converted
to 36-style preferences.
use separate var names for convertedKeys & convertedKeysMap
Merge pull request #6550 from adobe/dangoor/6541-leave-prefs

Fix for #6541 that leaves preferences in place after conversion.