Multiple updates

Updates to gitignore, added migrations folder. Created many to many
relationships between Module model and studentOf, tutorOf etc in order
to solve the use of arrays issue in Person model. Added setting for use
of postgresql and not sqlite3 in settings.
Modified settings, ldap views, and renamed classes

Added LDAP backend settings, renamed LDAP files because of name clashes
in imports, and changed ldap base dn address
Merging changes to develop from feature branches

Re-factored models, and modified tests
Revert "Merging changes to develop from feature branches"

This reverts commit e390b6f08df16c9fbeb8c68c227f83223563cbbb.
Revert "Revert "Merging changes to develop from feature branches""

This reverts commit 91cf10a1c5a5a24ba6b127b1090ff8c3c96c07ab.
Added test, modified ldap settings, modified models

Modified models by re-factoring some errors that were there such as
classes having __unicode__ returns but were not models. Added more test,
the tests are for new added models functionality, and added ldap
settings to allow for communication with the server
Added test, re-factored models
all changes to models
Conflict resolution