Discourage usernames with repeated letters.

Also, prohibit usernames with "loves" as a substring.  This deals
with some unhelpful usernames that were created yesterday (aaaaaaa
and permutations of XlovesY).
Add test exercising username validation.
Merge pull request #78 from PencilCode/usernames

Discourage usernames with repeated letters.
Bring frame.html in line with editor.html.

The editor no longer needs to load turtlebits.js in the topmost window;
remove this.
Merge pull request #79 from PencilCode/fixframe

Bring frame.html in line with editor.html.
Bowercopy update to latest.
Bowercopy update.
Add gym.pencilcode.net docs staging area.
Propagate bad-substrings.txt to wsgi
Bowercopy update jquery-turtle, ZeroClipboard, require.js.

Jquery-turtle brings in miscellaneous library fixes, plus the Webcam
class.

ZeroClipboard is upgraded to 2.0.1, which has a minor API change.
Code updated to match the new API, and Gruntfile updated to reflect
the new dist layout.

No major change in require.js.
Bowercopy update: latest jquery-turtle.
Discourage too-long usernames.

Usernames longer than 20 chars look like they aren't mnemonic,
so discourage these longer names.

Also, discourage names that look like possible email addresses
(ending with a common domain suffix).
More informative message when rejecting "myemailatschooldotedu".
Merge pull request #80 from PencilCode/shortnames

Discourage too-long usernames.
Remove console.log line.
Blue for links in the share dialog.
Merge pull request #83 from PencilCode/bluesharelink

Blue for links in the share dialog.
Merge pull request #82 from PencilCode/embednolog

Remove console.log line.
Fix ZeroClipboard integration on production.
Bowercopy update to latest jquery-turtle, zeroclipboard.