fix broken style for ubuntu
fix a conflicting shortcut "D"

- "D" is used for delete action
- open and download have the same place and open has a shortcut key "O"
- this will tell download action to use shortcut key "O" as well
Update welcome-dialog.ui

Fixed grammar
Merge pull request #351 from alvonellos/patch-1

Update welcome-dialog.ui
Add new sync error string "Files are locked by other application".
Add new sync error string "Files are locked by other application".
update translations
Merge pull request #348 from haiwen/fix_conflict_shortcuts

fix a conflicting shortcut "D"
Merge pull request #347 from haiwen/fix_broken_style_for_ubuntu

fix broken style for ubuntu
remove debug prints
add initial multi-selection supports

only download and remove actions are allowed on the multi-selection.
unselect the removed rows in FileTableView
chaneg background colors and its painting delegate
QStyledItemDelegate::paint should never be used
Merge pull request #355 from haiwen/change_background_colors

chaneg background colors and its painting delegate
Merge pull request #352 from haiwen/sync-err-str

Add new sync error string "Files are locked by other application".
handle cancel event correctly with PostFilesTask
Merge pull request #357 from haiwen/handle_cancel_event_correctly

handle cancel event correctly with PostFilesTask
Merge pull request #343 from haiwen/feature_multi-selectable_file_browser

[RFC] add initial multi-selection supports
implement autostart support for osx