Use simple multiplication for squaring. Fixes BUKKIT-4836

This change adds a method to NumberConversions for squaring and
replaces uses of Math.pow(..., 2) with the new method for efficiency
reasons.
Update maven compiler to 2.3.2

This change removes a redundant addition of source encoding and makes our
compiler match the current maven default. This amends the commit
52215c617166dddbe52cf7ee8d37964dc948f753

Upstream issue http://jira.codehaus.org/browse/MCOMPILER-70
Fix format of 9cba5ff2b8b3b80068f464fc4cecc3e97b7cf4f1
Display command-message closing bracket correctly. Fixes BUKKIT-4894

This commit adds proper formatting to the closing bracket used when certain
commands send messages to all players with the broadcast-channel
permission.
Updated version to 1.6.4-R1.0 in pom.xml for RB.
Updated version to 1.6.4-R1.1-SNAPSHOT for development towards next release.
Updated version to 1.6.4-R2.0 in pom.xml for RB.
Updated version to 1.6.4-R2.1-SNAPSHOT for development towards next release.
Merge pull request #2 from Bukkit/master

updating