Remove version number from minified file name

Declaring it here makes it a pain to version control.
Bump version

Use "-beta" qualifier to designate transitional state.
Add support for content of arbitrary length

Browsers implement varying limits on the length of URLs. Internet
Explorer 8, for instance, does not support URLs longer than 2,083
characters[1].

In browsers that do not support the `srcdoc` attribute, store the
content in iFrames' `srcdoc` attribute and use the script-targeted URL
to access the attribute value.

[1] http://support.microsoft.com/kb/208427
Update documentation

Include latest information about browser support.
Formalize dependencies
Fix .gitignore file

Do not ignore environment-specific files. Ignore external development
dependencies.
Upgrade to Grunt 0.4