1.5.1 port

Saw on the minecraftforge forum that you wouldn't get to a 1.5.1 port quickly so I had a quick go at it. 
So here you go, looks to be working fine on my single player world. though had to also fix a long file issue on the tar compression methods, when I was doing a full backup (caused by the dev mod file itself).

I had to rework the build.xml file a bit so that the forge scripts do all of the work, which means that you do not need to list all of the needed libs as they are already in the correct place.

I have bumped the version to 1.1.x to indicate that it is for 1.5.1, not just 1.4.x.

Forge version used was the latest at the time 7.7.1.656.

Chris.