Change handling of Motor Digests. The computed digest value is now stored as a membe...

Change handling of Motor Digests.  The computed digest value is now stored as a member variable in the ThrustCurveMotor and avaliable through the getDigest() method.  getDigest() was added to the Motor interface.  All references to MotorDigest.digestMotor() were removed from the application.

The android db now stores the digest.  Also changed persistance mechanism for delays to store as comma delimited string.

The TestMotorLoader is now failing because the digests have changed.

git-svn-id: https://openrocket.svn.sourceforge.net/svnroot/openrocket/trunk@356 180e2498-e6e9-4542-8430-84ac67f01cd8