Fix usage summary
Added base unit 'bits'.
Update tests and fix URI parsing

Update URI parsing for BIP0072 compatability
Update tests for parse_URI
Shouldn't redo URI encoding
Merge pull request #747 from wozz/URI_tests

Update tests and fix URI parsing
Merge pull request #743 from pooler/usagefix

Fix usage summary
Merge pull request #746 from slush0/bits

Base unit 'bits'
fix #745
try pyasn1-modules as well
fix #744
add support for RSA_SHA256