Prefix all attributes with asb_ to avoid collisions

I didn't test this much beyond the sample app and my own app, but it worked for me and resolved the attribute collisions with the v7 appcompat library 21.0.0 (and other libraries) as described in issue #42. Unfortunately, this is not a backwards-compatible change so you may want to put a warning at the top of the README and increment the major version number if you choose to merge.