prototype on dropbox oauth WIP
oauth for dropbox WIP. next step is to finish the item onclick action and action menu
added download db function
dropbox oauth finished logout and upload. need to refactor the code. main features completed WIP
dropbox oauth WIP
Merge branch 'master' into xinxin_anymemo
refactor dropbox oauth code
fix a bug in dropbox oauth
merge master to xinxin_anymemo
per haowen CR
add feature to  upload to and download from anymemo dir
Merge branch 'master' into xinxin_anymemo

Conflicts:
	res/values/strings.xml
Rus translation update.
Update per Haowen's CR. Add better error handling

per haowen cr

further refactor the code

add better error handling
Fix the Quiz's "uncategorized" text.
Add text to the category button in quiz launcher.
Randomize the cards when quizing by category.
Display help in the Gesture dialog fragment.
Merge branch 'xinxin_anymemo'

Conflicts:
	res/values/strings.xml
Change the error message in DropBox downloader.
Downloading a db from DropBox will back old db if it exists.
Do not refrash list if there is no successful upload in DropBox.
Fix the exception handling in Dropbox.
Fix the bug that Google Drive shows Dropbox messages.
Bump version to 9.999.3