Add prefixfree and adjust CSS

With prefixfree you don't need a devserver or anything to get the same look as
in the version built with gulp.

Changed `columns` to `column-count` to counter prefixfree bug here due to CSS
naming weirdness: https://github.com/LeaVerou/prefixfree/issues/54

fix links to app-spec.md

and "template/".

The rest of the gh-pages links look okay.

Gulp build chain

Fix #972

The script is going to build `master` with `gulp` on every push and, if
successful, push the resulting `dist/` to `gh-pages`.

Yay, autoprefixer!

Based on Web Starter Kit

removes uncessary pragma - react

React - Unused element footer#info

React comments - limit to 80 columns

Issue 952: fix styling for all/active/completed buttons

browser-tests - disable timeouts for Mocha 1.21 … 

Commit 17a3ca7e set timeout to Infinity,
but this still doesn't solve the issue reported in #961 if you use Mocha
1.21.

This commit changes the config for grunt test run to
`enableTimeouts=false`, and documents the equivalent command line switch
(`--no-timeouts`) for mocha executable.

Polymer: Updated to use core-*

Browser tests no longer mandate hidden items are removed from the DOM

Fixes #908 - tests no longer mandate hidden items are removed from the DOM
Closes #790 - these were implementations that implemented routing via hiding items, rather than removing from the DOM

Regressions:
#949 - discovered that exoskeleton is badly broken
#858 - added typescript-backbone (might not be a regression, more likely missed earlier)

Updated knownIssues based on recent updates to puremvc, react, soma etc ...