Change CommandExecuteTask to run all commands in order
Removed one too many zeros
Changes to ChatManager

+ HashSet provides faster contains
+ HashSet only allows the an object to be added if it does not already
exist so contains is not required (This also means that enable/disable
chat methods should give increased performance)
+ Added a method for the chat manager which clears players from a set of
players who have had chat disabled. This is to prevent the disabled chat
set from being edited in a manner which we can not control
+ synchronized each method to prevent ConcurrentModificationException
from being thrown if someone with disabled chat quit & someone talks at
the same time
Added 'target' to .gitignore to prevent class files from being commited
Speed up of buy command listener

+ Fails quicker than previous implementation if the command is not the
buy command (~1/3 of normal time)
+ From tests if the command is the buy command the command process is
started in equivalent time.
Removed unneeded contains method

Set.add(Object o) only adds the object if it does not already contain
the object.

Skipping the contains saves a bit of time.
Cache Chat strings.
Fixed issue with new buy command handling

+ Assumed the player added an argument hence a space would always be
present. Which is not always the case.
+ Now checks the command along with one of two possibilities, either the
player types '/buy' in which case the message and command strings will
be the same length. Else the player adds an argument where the character
after /buy will be a space
Mavenized!!
Merge pull request #8 from ShadowDog007/master

Performance + Bug fixes