Remove welcome project duplicate fix

Clean up welcomeProjectsFixed code - Issue #2823
Customize styling for Quick Open

Add box shadow, more fonts, align vertically with input.
Reveal hidden cursor on lint

Reveal potentially hidden cursor when linter panel opens. Does not
include cases where the cursor is not visible in the editor. References
issue #3003
Fix error

Fix error caught by Travis build. For pull request #3368
Make sure editor is open

Make sure editor is open and active (i.e. not switching files/projects).
Change mustShow scope

Change the scope of mustShow to match that of later reference.
Use `cursorCoords()` instead of line numbers

Use the more efficient & accurate `cursorCoords()` function instead of
calculations from line numbers.
Merge branch 'albertxing/3003' of https://github.com/albertxing/brackets into albertxing/3003