Added full OpenID support, added manual semester addition/deletion, module positioning

Note: Bootstrap library updated to latest version

app.yaml
	-openid_login.py now handles /_ah/login as well

css/main.css
	-adjusted font size of all bootstrap tooltips
	-all browser-specific CSS rules added.
	-OpenID login page rules defined.

css/skilltree.css
	-fixed definitions for #moduleInfo

images/openid
	-added icons for all supported OpenID providers

openid_login.py
	-added proper OpenID logic
	-added create_login_url, which merely returns an absolute path to "/login"

scripts/login.js
	-basic javascript that initialises all sign_in_buttons by disabling their default behaviour

scripts/skillTree.js
	-all moduleBoxes are now droppable on each other
	-they can no longer scroll #moduleListView
	-faculty and workload are now recorded
	-fixed minor code errors
	-added slimScroll initializers to the moduleAccordion children
	-#moduleAccordion now is only initialized with heightstyle: content

scripts/skillTree.js
	-notifications now have a 5-second timeout.
	-addSemester() and removeSemester() added, and will shift modules accordingly.
	-trimSemesters() should no longer be called in any part of the file.
	-setException() now sets the button state itself.
	-removeAssignedModule now removes the single prerequsite with only a warning, and sets the exception flag accordingly.
	-.moduleBoxes in the same semester will now swap positions when dropped onto one another.
	-added click handlers for new menu items in the semester settings
	-modules in the list now have working tooltips
	-semester number bugs fixed
skill_tree.py
	-new students are now initialised with their e-mail addresses

templates/Home.html
	-OpenID login integrated
	-Button text changed if not logged in

templates/OpenID.html
	-jinja2 template for the login page
	-can adjust itself not to return redundant tags if embed argument is specified
	-autogenerates buttons for each provider

templates/SkillTree.html
	-OpenID login integrated
	-moduleInfo DIV reorganised
	-semester dropdown menu now has more links