Refactored DatabaseConnection

Changed a "==" to a ".equals()" because we're comparing objects not
primative data types.
Added *.stf to gitignore

Since we'll be working on strings which are provided by the client,
there is no need to commit any .stf files.
Fixed the for loop inside receive()

SoeProtocolHandler was not returning any list in most of the cases.
I have put a condition for the decode() method returning null. This
should stop the NullPointerExceptions.
Merge pull request #7 from MrDinnertime/master

Refactored part of DatabaseConnection. Updated gitignore. Fixed a small part of UDPServer.