Not allowing completed appointments to be deleted
Adding date stamped and form code to contact forms

Contact forms may now be date-stamped.  If this date is recorded during
data entry then a "consent to contact stamped" event will be added to
the participant (if the event exists).  Additionally, a new "grouping"
column has been added to the participant table which is defined by the
code selected during the data entry phase.
Adding check for invalid start/end dates in calendar feeds (javascript)
Fixing bug in 'consented to provide HIN' token attribute
Fixing bug in survey_manager dealing with completed interviews without an assignment
0000546: Date of In home appointment
Creating new database/limesurvey/surveys::get_token_attribute_names() method

Limesurvey 1 and 2 store token attributes differently.  This method detects which
method is being used and decodes the values appropriately.
Updating error codes
0000545: Call back calendar- indicate IH or DCS
Fixing miss-named method call in survey_manager
Merge remote branch 'origin/release' into develop