vectormath: integer-cast pointers using (uintptr_t) instead of (UINT8)

   - avoid warnings, should be more portable across 32bit vs 64 bit
      machines, use (size_t) as fallback for platforms without <stdint.h>
   - fixes #1182
Move binary orbit parameters into PulsarDopplerParams

- one parameter structure for both isolated/binary CW signals
- no longer need to allocate free memory for *orbit field
- new convention: asini >  0 --> binary pulsar
                  asini  = 0 --> isolated pulsar
- PulsarSignalParams, which uses deprecated PulsarSourceParams,
  gets its own inline copy of BinaryOrbitParams fields, to
  ease backward compatibility with GeneratePulsarSignal()
- otherwise, all codes converted to using binary parameters
  from PulsarDopplerParams
- removes restriction on binary support from XLALComputeFstat()
- adapted XML (de)serialisation functions and test
- add checks on value of 'asini' to a few functions as appropriate
- passes 'make distcheck'
- refs #1161