Fix for "non English CurrentCulture" and "Run on empty" crashes

Hi Mark, 

I toyed with the Pad this morning and ran in some problems...

Hitting "run" without any query triggers a NullPointerException. Somehow - since the button is under the ConnectionString - I always want to enter my connection string and hit run first >_< I seldom use the pad, but when I do I always run into that one again. I added a check in commit e01d489c38f397c22251e5ceab4958bab9a6efa4 to run the query only if some text was entered.

EntityFramework does not seem to like the German CurrentCulture settings I have on my computer here. In order to bypass this I suggest programmatically setting the culture to "en-US" (or whatever works). That's what I did in commit 2d0c7035e49b0f12cadb8d06df58af671f65ace2.

This is my first official pull request so feel free to hit me back ;)

Cheers!
Tim