Update requirements, including Django 1.6
As per Django 1.6 [release notes](https://docs.djangoproject.com/en/dev/releases/1.6/) tests must now use full Python dotted paths when passed to ./manage.py test
Enhancement cellcounter/cellcounter#191

Cellcounter now stores an history of keypresses in an array, allowing ```Backspace``` key to undo the last keypress, whether it was normal or abnormal in cell type.
Update help text to include new role of ```Backspace``` key.
Remove whitespace line for easier readability
Prevent default backspace behaviour (i.e. navigate back)
Merge of master-JS changes into history feature branch
JSHint cleanup of dot notation references
Merge pull request #216 from jvc26/cellcounter/cellcounter#191

Enhancement cellcounter/cellcounter#191
Update Django to 1.5.5
Merge pull request #221 from jvc26/django-security-update

Update Django to 1.5.5
Fixed merge conflict in requirements.txt, merge to bring up-to-date with upstream
Fix for cellcounter/cellcounter#220
Merge pull request #222 from jvc26/cellcounter/cellcounter#220

Fix for cellcounter/cellcounter#220
Merge pull request #208 from jvc26/update-requirements

Update requirements, including Django 1.6
Added barebones accounts app
Add register link to base template
Enable accounts app
Delegate accounts related URLs to accounts app
Merge branch 'master' into cellcounter/cellcounter#215