Add auto code completion (without press Ctrl+Space manually)

Disalbe auto code completion even there's only one option

Hide auto-completion if only one completion option and it's been typed

Support use tab key to accept code completion option
Press F key in 2d editor to center view to selected node

Press Ctrl+F to frame selected nodes in 2d editor

Change Frame Selection hotkey in 2d editor from Ctrl to CMD for Mac compatability
Merge pull request #374 from marynate/PR-code-complete

Add auto code completion (without press Ctrl+Space manually)
Merge pull request #375 from marynate/PR-2d-editor-F-key

Add F and CMD+F hot key for center/frame selected node(s) in 2d editor
call during autocompletion
remove degud output
Merge pull request #379 from jonyrock/auto_brace_complete_open_bug_fix

call during autocompletion
Add lock and group icon to scene tree editor
Merge remote-tracking branch 'upstream/master' into dev

Conflicts:
	tools/editor/plugins/canvas_item_editor_plugin.cpp