CotEditor for Mac

What's new in this version:

New Features:
- Add a command “Select Word” (⌘D) to Edit menu

Improvements:
- [trivial] Display default setting values as the input field's placeholder for instance highlight delay option when empty

Fixes:
- Fix an issue where editor area could be tuck under the line number view
- Fix an issue where changing the selection by shortcut ⇧→ just after shortcut ⌘⇧← expanded the selection to a wrong direction
- Fix an issue where page guide did not update when font changed