Updating README.md contents

Fixing typos and updating descriptions to reflect current developments.
fixing formatting of patch instructions in README
Check that view or collection isn't submitted to another assignment, before submitting
Don't display empty collections in the selection list
Check that a selection is present before trying to lock it
Better error message when a view/collection can't be submitted
Fixing bugs encountered when trying to save a collection as a draft
Check for whether get_user_flas() returned boolean false
Updating mahara patch to reflect latest patch in gerrit
Fix declaration compatibility issue (bug #6).