Added new functions to editor api - set/get_text so the
original form text can be determined from an editor.

When calling use_editor() you should first call set_text() with
the text that will be inserted in the form element.

There is also a new scheduled task for cleaning Atto autosave drafts.

If the files in the draft area have been modified more recently than the timestamp
of the draft - do not restore the files, or you will delete any newer files. We
cannot really guess here - merging the 2 lists of files will be wrong.

Addresses responsive inconsistency on Firefox, also fixes display
of names which are long and don't have whitespace to break on.

This commit adds a new scenario to verify that the option
to turn edition of subscribers is not available anymore
for forced-subscription activities.

It also gets rid of the @javascript tag in a just introduced
scenario not needing it.

Based on a patch by Davo Smith of Synergy Learning

RSS feeds can fail, either permanently or temporarily.
After this patch if a feed fails it will not be tried again in the next cron run.
If it continues to fail the delay between tries will be increased.
When a feed succeeds it will go back to being fetched on each cron run.

This should make the CRON process for RSS feeds finish faster when
there are lots of invalid feeds.