v0.6

Now with experimental Neptune R900 support!

Changes:

• eb2b055 Fix galois field package path.
• a88bbf1 Simplify symbol decoding process.
• 57e1be9 Add gf package license.
• 6f3d973 Integrate R900 decoder.
• 8a57030 Add R900 decoder.
• 19dadbb Move CenterFreq to PacketConfig for per protocol defaults.
• 8865d2e Update travis-ci configuration.
• 979aa93 Fix rounding problem in parser.
• 0c47867 Move s to correct scope.
• c9c1d99 Simplify duplicate packet check.
• 3c66161 Separate demodulated signal from filtered signal.
• dbb4227 Set actual field lengths.
• 86a2abf Refactor for signal access from parser.
• 11d5802 Rename for later protocols.
• 03369d1 Simplify packed byte array length calculation.
• 3bcb52b Fix packed byte array length calculation.
• b326ea9 Limit checksum to valid length.
• 2d12445 Update usage.
• 76ee4cb Update badges.
• ea81369 Add new error case for SCM parsing.
• 2b055fc Convert filterid and filtertype flags to comma-separated lists.
• ed47c5c Fix NewDataFromBits
• 9994aaa Add calculator for valid symbol lengths.