handle NtUserCall*Param corner cases: win2k, unknown calls

_From [bruen...@google.com](https://code.google.com/u/109494838902877177630/) on December 29, 2011 20:32:33_

issue #484 added infrastructure for secondary syscall tables, added syscall
numbers for NtUserCall_Param for most platforms, and added handling
for the majority of NtUserCall_Param calls.

this issue covers finishing up some corner cases:
- get the syscall numbers for Windows 2000
- verify all the intermediate calls for Windows 7.
for issue #484 I verified calls at a number of points throughout the list.
- determine the currently-unknown calls: there are a small number whose names
and params are unknown

_Original issue: http://code.google.com/p/drmemory/issues/detail?id=728_