HashValue.h
- Removed FastAlloc.h , not required for dclib
- Removed Encoder.h, not required for dclib
- Removed tr1 definition, not required for dclib

MerkleTree.h
- Removed Encoder.h, not required at all
- Re-use the Hasher rather than re-allocate it.
  Requires the TigerHash.h change.

TigerHash.h
- Add reset() so a TigerHash can be re-used.

TigerHash.cpp
- Replace stdinc.h and DCPlusPlus.h with compat.h for dclib
- Use autoconf to determine if big endian.
- Remove unused tigerCompress function, which was doing nothing
  besides expanding that macro one more time.
- Always use TIGER_ARCH64 code. It works and is slightly more efficient
  even on 32bit systems.

