disable save button during image uploads

closes #1661

- disables save button at beginning of image upload
- enable save button at image upload fail, at image upload and download success and also at dropzone init
Fixes showing tag suggestions and tag container padding

fixes #1774
- Delayed showing the tag suggestions popup unless matching tags were found
- Changed the padding-left on the added tag container to 8px from 20px to fall in line with the left shadow overlay
Modified github.js to ensure __ isn't escaped at beginning of line

    fixes #1791
Added handling for undefined errors and test coverage

Fixes #1827
Disabled styles for disabled buttons

Duh
Adds ability to quickly get to post’s edit page

fixes #1810

- updates frontend.single route to accept ‘edit’
as the last param

- updates controller.frontend to handle redirection
only when we would otherwise have rendered the page

- added unit tests for this behavior
Fix {{content words=“0”}} to actually return 0 words

fixes #1796

- adds in a workaround to the weirdness that currently
exists in downsize module
- adds tests
Remove express server from grunt test-coverage

- currently the coverage report only runs for unit & integration tests, and these don't need the express server.