Fix up web.xml config

Add missing WebServlet annotation to JavascriptConfigServlet class, for
consistency.
Remove redundant configuration items from web.xml, as on Tomcat 7 with
default settings these cause the following error:
java.lang.IllegalArgumentException: The servlets named
[JavascriptConfigServlet] and
[net.socialgamer.cah.servlets.JavascriptConfigServlet] are both mapped
to the url-pattern [/js/cah.config.js] which is not permitted
Merge pull request #43 from uecasm/leavegame

Improvements to error handlers
Merge pull request #42 from uecasm/webxml

Fix up web.xml config (issue #36)
Update README

Add Tomcat 6 issues to readme.
Fix z-index for game options so you can actually click into the password field when there are a lot of cardsets.
Increase max games to 250.
Resolve confusion between ns and ms, which should not have actually changed much except the fuzz time around idle returns (which seem to never happen in production anymore).
Increased number of messages returned at one time to 20.
Increased wait time for more messages before returning to 50ms.
Remove several game list refresh broadcasts:
- never broadcast when a player joins a game (unless it's a new game)
 - removed a duplicate broadcast in this situation as well
- never broadcast when a player leaves a game (unless the game no longer exists)
- never broadcast when a game's options change (unless the state of it having or having not a password changes)
- DO broadcast when a game resets to the lobby state (we were broadcasting when a game started but not when it ended)

In an effort to reduce deadlocks, do not actually hold a lock over the list of players in a game and instead make a copy into an array for looping, in several locations.
add more custom card sets
Merge latest upstream code.