Use already-made gravity form rather than hand-rolled survey.

As a stop-gap, I'm going to simply use a gravity form I already made
rather than put together a new form.
Merge remote-tracking branch 'origin/master'

Wanted to add something to the last commit, after I'd pushed it.
Remove inclusion of globals.php in the main hch-survey.php script.

Those globals are only the names of the databases, and they're
not needed by hch-survey.php. So, I took them out, in case they
pollute the namespace of this script.
Use Wufoo-generated html form code rather than Gravity forms shortcode.

I generated html and css code from Wufoo, and then pasted that into
the main-survey.php script. At the moment, this simply displays
the survey. I will next work on the back end processing.
Add check for whether all questions were answered, in survey.

New functionality, to check if all the questions were answered,
and if not print a message to the top of the screen.

This also includes the ability to re-print the answers already given
(only for the name and email, not for the yes/no; those get cleared).
Implement question-analysis and saving of user info to database.

The main-survey.php script now properly analyzes the answers
given by the users and saves the data to the database.
This means
1) Collisions in email address are checked; if they occur, no
save is done and an error is printed to the screen
2) The person's answers are analyzed, and they are tracked
into the proper group.
3) All the data (name, email, group_id, track, date submitted)
are then saved in the database.

This also necessitated altering the database-creation code
in the de-activation.php script.

TODO: the group_id is not being properly saved (it's just a dummy
value), so I need to couple the reading of the gid from the query
string with the saving.
Implemented proper saving of group id to health_data_table.
Refactor admin-page.php into functions, to get rid of usage of globals.
Implement redirect to thanks page after successful completion of survey.

This involved moving the analysis section before the drawing section,
and adding a wp_redirect call within the analysis section.
Add ability to download user data, from admin page.

Admin user can select a group, and download a csv file
of the data for all the users of that group.

Lightly tested, and appears to work.
Fixed problem: admin page always reported group exists, even if new.

Thanks to a mis-ordering in the admin-page code, when a new group
is created, the admin-page always thought it already existed. So
even though the new group got properly created, the user was
told it wasn't.
Give survey data csv file more descriptive name.
Add explanations to admin-page.
Alter redirection after Paypal login, so user goes directly to the
survey.

Rather than going to a 'confirmation' page, then to the survey,
now the user goes from the paypal login directly to the survey.
This avoids the possibility of the user paying, but not completing
the sign-up process.
Display payment total in the paypal login screen.

In order to have Paypal display the amount the user will be
charged, when the user is logging in with Paypal, I added
a part to the query string in the Paypal url.
Remove a, now redundant, else statement.

The else was a remnant from before the user got redirected
from Paypal directly to the survey page (before, the sign-up
page had to determine if the user was coming to it for the first time,
or if they had been redirected from paypal).
Add paypal image for link.

The user will now see a paypal button to take them to sign-in to paypal,
rather than simple text.
Improve validation of survey form for paying users.

If-statments needed to be updated so that a customer who
has come from Paypal will have their form fields properly
validated, without being charged until the data is saved.
Add paypal function script (should have been done earlier!).

A few commits back, I factored out the CallPaypal function, into
its own script file. however, I forgot to add it to the repo until
now.
Add the ability to set Paypal info in the admin page.