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
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.