Add basic working version of backup/restore
Add fs-extra package
Add GrainInfo struct to grain.capnp and persist it through backup.

Backup also includes log now, although it isn't used in restore.
GrainInfo is encoded and is named metadata in the archive. The sandbox's
data now all goes into a folder called data.
Change restore to be a global function. Also add icon for download
Various fixups to backup/restore
Add recent build files to .gitignore
Make grain's title be the filename when backing up
Fix up error reporting for restore and fix a bug with type of appVersion
Replace usage of single quotes
Various fixups following Kenton's code review
Change query for restore to only look at user's installed apps
Change filesystem calls in backup/restore to be async
Fix grainId to be 22 characters in `restoreGrain`
Add fs-extra link/licensing to about page
Fix usage of single quotes, part 2
Simplify UserAction query in restore

There's only ever 1 installed version of an app for a user
Update license in backup.js to match the rest of sandstorm
Change UserAction query to only search current user
Merge pull request #28 from jparyani/backup-grain

Add backup and restore functionality