Use a real IRC object in some tests.

Additional functional tests of window.irc.IRC will need a full
object embedded in these tests, so make use of a real one rather
than an anonymous skeleton object.

While here, do some major CoffeeScript cruft cleanup.
Add a primitive but working WHO command.

Output goes to the server window. A smarter extension of this logic
could put the output of currently-joined channels to their windows,
and all else to the server window.
Escape HTML in command help so that <argument> is displayed.

Help messages, in order to have columnar output, are displayed
with HTML enabled. Strings which might contain <> characters
need to be properly escaped.
Fix regex in ScriptHandler.isValidName().

A bare / was in the character class, which may _work_, but makes
IDEs complain loudly. Escape the slash character to make it a
proper valid regex.
Merge pull request #198 from tvierling/who_command

Add a primitive but working WHO command.
Merge pull request #199 from tvierling/help_escape_html

Escape HTML in command help so that <argument> is displayed.
Merge pull request #204 from tvierling/script_regex

Fix regex in ScriptHandler.isValidName().
Merge pull request #197 from tvierling/test_cleanup

Use a real IRC object in some tests.