btle: make UUID.getCommonName() work and use it in __str__() methods
btle: move check for helper exe to __main__, for ease of unit testing
bluepy: update README.md
added __init__.py in order to turn bluepy into a python package
Merge pull request #9 from panizza/master

added __init__.py in order to turn bluepy into a python package
btle.py: flush pipe to helper after writing, fixes hanging on Python3.4
btle.py, sensortag.py: bytes vs string fixes for Python 3.4

Note I'm replacing chr(xx) with struct.pack("B", xx), so that
write data is 'bytes' on Python3.4, not a string. Passing a string
to Characteristic.write() is deprecated on 3.4, as not all data
blocks can be represented using the UTF-8 encoding of a valid string.
btle.py: ignore notifications sent to us by the helper

This stops btle.py throwing an exception; note this commit does
not let you do anything useful with notifications yet.
Notes for (tagged) release 0.1.0
bluepy: add .gitignore (github issue #17)