Adding first rudimentary version of tagging and filtering. New users get three tags: morning, afternoon and evening. At the moment, one can not change these tags or add new ones. There are also some problems: tagging a newly added task, also tags one of the existing tasks. Also, when having an active filter and removing the corresponding tag from a task, that task is immediately hidden, although you are still editing it.
Merge branch 'develop' into toebu-tags-filters

Conflicts:
	src/app/index.coffee
	src/app/tasks.coffee
	styles/app/index.styl
	views/app/index.html
	views/app/tasks.html
rename user._tagFilters to user.filters
for now don't live-bind to {#each _user.tags}. There's a derby bug
here, so we'll have to refresh when users add new tags until we get
that fixed
add new tag
add tag-editing context (add new, delete). still have to refresh after everything, do to the live-bound each bug
Merge branch 'tags' into develop

Conflicts:
	src/app/index.coffee
	src/app/tasks.coffee
	styles/app/index.styl
	views/app/index.html
	views/app/settings.html
	views/app/tasks.html
reset dom on tags instead of location.reload()
new tag sets _newTag to '', reset dom, static-bound tag loop
tags: use select combobox instead of dropdown, easier code & mitigates
some css issues
tags: some visual cleanup of the filter bar
tags: cleanup, prevent bug for multiple tag-creation
tags: use icon-pencil for editing
tags: eff it, refresh after saving tags
tags: add tags legend to task meta