#494 Allow Add New Talk button to create an empty editable talk

Allow Add New Talk button to create an empty editable talk.
This feature will eliminate the need for the Save Talk button.

Fix issue #494
Related to issue #427

Related proposal:
https://docs.google.com/document/d/1VdPLpdIgteMfr1l7TPIZQ1M5XUKcy7ffVWu41t5zvjk/edit#