tweaking ace editor
temp commit
Merge branch 'master' into ace-work
finish ace tweaking; fix an issue with restoring scroll position
add a gradient background to the menu button
Remove debuggin leftover + remove redundant </input>
Merge pull request #336 from ussuri/minor-fixes

Remove debuggin leftover + remove redundant </input>
Replaced remaining <button> -> <spark-button>
Merge pull request #337 from ussuri/switch-buttons-to-spark-button

Replaced remaining <button> -> <spark-button>
convert to using css margins
Merge pull request #334 from dart-lang/menu-background

add a gradient background to the menu button
Improve ImageViewer behavior (Fixed #335). Fixed naming of non-public methods, ivar and accessors.
merge to master
Merge pull request #316 from dart-lang/ace-work

Ace work
archive failure message
Fixed nits
Merge pull request #341 from sunglim/7z_message

grind archive failure message
Merge pull request #342 from dart-lang/windows-build

Windows build
Fixed some behaviors
Merge pull request #340 from dinhviethoa/335-image-viewer-ui-cleaning

Image Viewer cleaning. (Fixed #335)