Streamline the API

The API originally followed the pattern of Urban Airship’s public API
v3, which included a wrapper object in each response, which provides
room for status and extra metadata.  However, it makes the inputs &
outputs asymmetric. This change strips that out, just using the raw
entity representations.

The main benefit? We can now easily import/export via the API with
curl, or similar simple HTTP tools. Dashboards can be copied from one
instance of Tessera to another simply by piping one curl command to
another.
Merge pull request #281 from urbanairship/api-streamlining

Streamline the API
Bump tessera-client version to match
Exception safety for template expansion
Update for new docs location
Merge pull request #283 from urbanairship/documentation-update

Update for new docs location
Versionb bump
flot legend margins
Added use of `{{dashboards-tagged ...}}` helper in the related dashboards markdown
Update actions registry to accept either a model object or a plain JS object
Add a prefix to the setPref() function
Fix flot y-axis format
Fixing flot tick label colors
Format flot timestamps with moment for better control
Tweaking flot borders to be consistent w/graphite renderer
Add custom legend for flot charts

Rather than a fixed number of columns, this effectively lets us have a
responsive number of columns, to make better use of space on wide charts
Move redraw notification into container.add()
Delete unused code
Minor rearrangement to keep related code together
Automatically create a new item action for dashboard items