Add-On - SMS Backup & Restore.

11/5/2015

v3.20:
- Added support for GMail API so there is no need to enter the username and password any more.
- Old Gmail support renamed to "GMail (Legacy)"
- Better handling of large email send failures.

v3.13:
- Updated Dropbox SDK as per their guidelines.

v3.12:
- Fixed bug where upload to Google Drive would create multiple folders.
- Updated styles.

v3.11:
- Fixed a permission denial problem caused by the previous update.