Add a timeout to server startup and the ping test.
Add the test plugin to the plugin manager, just in case.
Make UnknownHostException more low-key. They are to be expected.

Whenever the update procedure is ongoing, and the server temporarily 
lost connectivity to the internet (or more likely, dev.bukkit.org is 
down), a huge exception log will be printed in the console. See ticket
134 for a real life example.

This is completely out of propotion to the problem at hand (connection
problems), so we will replace the error log with a simple warning 
message.