Changed promises used for session export from Ext.ux to RSVP.
Created static utils class providing helper functions for promises.
Merge branch 'session_import_export' of https://github.com/felix-schmidt/arsnova-mobile into origin/session_import_export
Removed Dead Code and debug output in SessionExport.
Merge branch 'session_import_export' of https://github.com/felix-schmidt/arsnova-mobile into origin/session_import_export
Merge branch 'session_import_export' of https://github.com/felix-schmidt/arsnova-mobile into origin/session_import_export
Merge branch 'session_import_export' of https://github.com/felix-schmidt/arsnova-mobile into origin/session_import_export
Fixed bug with utf-8 encoding on session import.
Merge branch 'session_import_export' of https://github.com/felix-schmidt/arsnova-mobile into origin/session_import_export