Support for remote documents, icons and more playground improvements (PR

This closes #340 and addresses #325 (I leave this open for the moment till
the RDF icon is either included directly in FontAwesome or we make it b/w
as all the other icons).

Squashed commit of the following:

commit d867cf1fb3b6a310bef70ca9647f1cfaccd04b05
Author: Nicholas Bollweg (Nick) <nick.bollweg@gmail.com>
Date:   Wed Mar 26 22:43:09 2014 -0400

    rdf icon

commit d9f2db50f9cdef4657da3a08dccf7629152931c9
Author: Nicholas Bollweg (Nick) <nick.bollweg@gmail.com>
Date:   Wed Mar 26 22:16:14 2014 -0400

    typo

commit 241ed5ac3fec52331bbcc4379e114241f6e23e81
Author: Nicholas Bollweg (Nick) <nick.bollweg@gmail.com>
Date:   Wed Mar 26 22:11:46 2014 -0400

    styling of context copy

commit 1d0d691f0620917c633a5c6409b555b0932bb817
Author: Nicholas Bollweg (Nick) <nick.bollweg@gmail.com>
Date:   Wed Mar 26 22:01:49 2014 -0400

    permalink cleanup

commit d48e0966794d062b8c48e8d1872f8df03ab8b281
Author: Nicholas Bollweg (Nick) <nick.bollweg@gmail.com>
Date:   Wed Mar 26 20:50:45 2014 -0400

    cleaning up remote URLs

commit ee28a1e785bff51a0900f50008ff7ac6e8cb7da2
Author: Nicholas Bollweg (Nick) <nick.bollweg@gmail.com>
Date:   Mon Mar 24 23:26:09 2014 -0400

    permalink feedback

commit 054fa28197b0cc6082f5bbab6c4e2aee5afe8d4d
Author: Nicholas Bollweg (Nick) <nick.bollweg@gmail.com>
Date:   Mon Mar 24 22:46:46 2014 -0400

    more cleanup, UI quirks

commit d65f5dd7eb315acaf9e073b96521b6a52e4b097f
Author: Nicholas Bollweg (Nick) <nick.bollweg@gmail.com>
Date:   Mon Mar 24 21:13:22 2014 -0400

    using remoteURL for base, if available

commit 4d2b8539c7b085056678f60c3e056b216272e720
Author: Nicholas Bollweg (Nick) <nick.bollweg@gmail.com>
Date:   Mon Mar 24 20:25:35 2014 -0400

    hash permalinks, more icons, doc, return values

commit f804c6144304ab8f662f7c2f7390686b411ae336
Author: Nicholas Bollweg (Nick) <nick.bollweg@gmail.com>
Date:   Sun Mar 23 18:43:22 2014 -0400

    adding context copy