Offline add new Ecard

1. Implemented local database, independent of Parse
2. Right now the data base looks like:
id   |   stored   |     userID    |      notePath
========================
1             0          xObqpb23V         /sdcard/voice.vga
--------------------------------------------
2             1          fwWbozqEE         /sdcard/voice1.vga
=========================
3. If online, Ecard will be added normally. If offline, scannedID will
be stored in this database
4. Every time app opens, will check if there are unsaved scannedID in
the local database. If there is internet, add them.