Unknown flower ~

I love these purple little flowers that are growing thru from our neighbors side of the fence that separates our yards. I have no idea what the name of it is though. It has the appearance of Rosemary...but I know it is not Rosemary.  Below is a full view of the flowers and branches coming thru the fence. 

Unknown beauty ~

Starting to open up...

In full bloom.

I honestly do not know what the name of these lovely purple flowers are. They  grow on a small tree...anyone have an idea?