Move course tmp files from the course directory to WeBWorK's tmp directory.

Changed the default location of all WeBWorK tmp files to
.../webwork2/htdocs/tmp.  We only had to change where course tmp files
are put.  Thhey now go to .../webwork2/htdocs/tmp/course_name/
So .../webwork2/htdocs/tmp is set up in exactly the same way we
suggest people set up /var/www/wwtmp.  There is no real reason now
for people to have to set up /var/www/wwtmp.
Merge pull request #60 from apizer/master

Change default location of course specific tmp files
removed errant submodule references
Removed errant submodule references
Merge branches 'openwebwork-dev' and 'master'
Fixed OPL-update to use libraryVersion from \$ce  rather than a VERSION file
Changed cherry-picked from webwork2/master 4663e15316233ec81d56ff75ca7113d5ded9ca1b
CONFIG-README directions out of date and superceeded by directions in README"
Merge pull request #62 from aubreyja/master

Porting change to OPL-update in webwork2 to webwork2-dev
Added wwapache2ctl and webwork2.komodoproject to .gitignore (the last is a project file generated by an IDE I'm trying out).
Sometimes users change user_id's. Given a course_id, an existing user_id in that course, and a different user_id, this script will (a) create a user for the new user_id if the account doesn't exist and (b) will also copy all existing data in the database associated with the old user_id to the new user_id. TODO: Currently copies all user set and problem data, but does not yet copy achievment data. We also want it to modify answer_log data so that the new user_id gets the same past answers.
Add a cleanup routine to PG so that MathObjects that are part of the output or answer checkers are freed (in order to prevent errors about missing packages).
Merge branch 'master' of https://github.com/openwebwork/webwork2-dev into package_errors
Merge pull request #67 from dpvc/package_errors

Resolve "Can't locate package ... " errors for MathObjects like LimitedPolynomial
I think having the shebang line '/usr/bin/env perl' is more portable than /usr/bin/perl. It works on all *nix's and also allows for the script to work unmodified when a local administrator changes the perl path
Added code to back up existing answer_log and then replace old user_id with new user_id
Modified DB.pm to fix issue #68
Merge pull request #69 from aubreyja/master

Added change_user_id script, modified DB.pm to fix issue #68, other misc. changes
CAS authentication module, associated conf file and changes to Login.pm and Logout.pm
Merge pull request #70 from aubreyja/master

CAS authentication module. Note, this has been well tested at UC Berkeley with their CAS system and verison of webwork.  More testing, especially with this dev code, would be welcome.
Added support for URLs as provided in WWfeedback messages

I had inadvertently provided an older version of CAS.pm when submitting
the original version.  This brings CAS.pm up to date.  The only change
was/is to add support to keep params on the URL being sent to the CAS server
(so that URLs provided by WWfeedback messages work properly).