Merge pull request #25 from gopher-snakes-2014/anders_chart_spike

Anders chart spike
add delete method for untagging to event_tag controller
add delete route to hit untagging method in event_tag controller
add equal and opposit ajax method for untagging
create unselected class for distinction from new tags
create untag method for Event model
updated div classes in partials to match js model
reset model after each button click to prevent buggy rendering
move buttons outside of partial to retain their bindings
refactor create and delete methods to leverage terse active record
better variable naming for event model
reorder routes so that submit feature test does not get confused
organise event model methods
Merge pull request #27 from gopher-snakes-2014/untagging

Untagging
styling changes to acknowledgement page and logo addition
Add navbar for user navigation through site
Add footer to layout
Misc color changes to styling
Add placeholder div to homepage which will hold responses from various ajax requests
Add AJAX call to render login form by clicking login link
Add login/logout logic to display correct link in navbar
Reorganize CSS files
Add Rails AJAX call for event form submission
Separate student/parent ajax calls into new js file
Create admin_dashboard partial