Remove unneeded call to Handlebars.compile
Factor template handling into base view

Factor template handling in Backbone views into a base view,
``storybase.views.HandlebarsTemplateView``.  This is implemented through
``storybase.views.HandlebarsTemplateMixin`` which allows the view handling
capabilities to be mixed in to objects other than views.

This approach makes template handling more consistent and makes it easier
to swap out template engines if we ever decide to abandon Handlebars.

``HandlebarsTemplateView`` takes a ``templateSource`` property which is
either a string containing the template markup, an object with keys
mapping to template strings, or a function returning a template string or
hash of template strings.  When specifying an object, the main template
is identified with a key of ``__main``.

A compiled version of the main template is assigned to ``this.template``.
If an object was provided for ``templateSource``, a particular compiled
template can be retrieved using ``this.getTemplate(key)``.

Addresses #707
Merge branch 'hotfix-709-toc_toggle' into develop
Wrap Backbone modules in self-executing functions

Wrap Backbone modules in self-executing, anonymous functions.

This allows us to more safely use local variables in each module reducing
the repetition of things like ``storybase.builder.views``.

This commit also removes the dependency on Namespace.js. It included support
for things like asynchronous downloading of modules which we're not using.
Instead, we'll just create the namespaces explictly.

Addressess #710
Move Backbone app globals out of separate namespace

There wasn't any real good reason to have globals attached to
storybase.(viewer||explorer||builder).globals.  Instead, just attach them
to storybase.(viewer||explorer||builder)
Remove StoryHeader view

This was commented out and likely won't return.  Just remove it.  We can
use git to recover it if need be.
Remove console log statements

Remove console log statements in the builder. End users don't care about
them and they were cluttering up the console in testing. Now that the
builder is more stable, they're less needed.
Make viewer header not be position:fixed (#684).

Also make header box-sizing: box-border so horizontal scrollbar isn't
required.
Prevent wrapping in header-right menu (#702).

Prevents long usernames from wonkifying layout.
Merge branch '715-modal-viewer-toc' of https://github.com/patternleaf/atlas into patternleaf-715-modal-viewer-toc

Conflicts:
	static/js/viewer/views.js
Update changelog
Merge pull request #720 from patternleaf/702-long-usernames-in-header

Prevent wrapping in header-right menu (#702).
Update changelog
Merge fixes for #723 into develop

Conflicts:
	README.rst
Update initial section thumbnail lookup keys

In ``SectionListView.addSectionThumbnail``, wire up a one-time event
listener to update the thumbnail view lookup table's key to be the
section's id instead of its cid when the section is initially saved.

Addresses #725
Disable save button on 'do:save:story'

This fixes a race condition where the auto-save when leaving
the title text input and the save initiated by clicking the "Save"
button both initiate the initial save of the story via a POST to the
API.  This causes 2 story records to be created.

This commit updates ``LastSavedView`` so the state of the button is
updated on the ``do:story:save`` event rather than the click event.

So, when the autosave triggers the ``do:story:save`` event, the
button's state will be updated and disabled so it will not respond
to the click event.

Addresses #728
Invalidate cached places list when story places change

Addresses #730
Bump changelog for version 0.9.6