Fixed issue #1070
Added keyboard navigation to symbols explorer, now it allows to navigate
with cursors keys and when Enter is pressed go to definition (no more
click needed)
Fixed issue #1070 (Clean up explorer after last tab is closed).

Added keyboard navigation to symbols explorer, now it allows to navigate
with cursors keys and when Enter is pressed go to definition (no more
click needed)Please enter the commit message for your changes. Lines starting
Fixed comments
Merge pull request #1078 from malderete/master

Fixed issue #1070