Removed some resolved 'fixme's
Merge remote-tracking branch 'upstream/master'
Merge pull request #10 from felixmo/master

Clean up some resolved 'fixme's
Implemented failure blocks for operations
Added alerts for certain failures (ex. incorrect credentials, refresh failed, upload failed, etc.)
Only enable 'Upload' button when there are files queued for upload
Merge remote-tracking branch 'felixmo/master'
Merge branch 'master' of https://github.com/dz1111/Commons-iOS into unittesting