On Windows supply python executable to launch
On Windows supply python executable to launch

Solves the silent launch failure in bug #4

alexkolar/Wooey,waytai/Wooey,wooey/Wooey,waytai/Wooey,wooey/Wooey,waytai/Wooey,wooey/Wooey,hottwaj/Wooey,hottwaj/Wooey,alexkolar/Wooey,hottwaj/Wooey,alexkolar/Wooey,wooey/Wooey