Abp precision

Changed code to use g_NMEAAPBPrecision instead of g_NMEAAPBXTEPrecision. Changed Options text on Connections tab to reflect this. Removed the hidden setting for NMEAAPBXTEPrecision as it is really redundant. If the Bearing needs to be 2 decimal places then the XTE should really be the same. If there is a true need for a difference between XTE and Bearing then I will add a line to the options page to reflect this.