Changed Terminal Applescript

Changes:
 - As I see it, there's no need to check if Terminal is running - if it isn't, the Cmd-T will open a window, if it is, Cmd-T will open a new tab. 
 - There's no need to run 'clear' - a new tab will be empty already.

This fixes a problem I was having where, if Terminal wasn't running, a window wouldn't be created, so the ssh command wouldn't run. I was getting the error 'Can't get window 1' when running from Applescript editor.

I haven't called this a bug fix, as I'm on 10.9 and some problems are expected. However, I don't think this will break any other OS X versions.

I have only tested this on 10.9, will test on 10.8 shortly. Again, I can't see any problems with other versions, but would definitely appreciate testing from someone on earlier versions.