Take advantage of plString more in hsStream's String I/O functions
Add string split and tokenize functions
Convert SDL (mostly) to plStrings
Add support for Visual Leak Detector, since valgrind doesn't support MSVC
CoreLib fixes for Linux.
Fix plResManager stricmp.
Fix a whole bunch of clang warnings.
Get rid of const char* warning in plPythonPack.
Corrections as proposed by @branan.
Fix those scary SystemErrors we see in DS

As it turns out, my old OnServerInitComplete fix didn't check to see if
the script had an OnServerInitComplete method. So, when we called that
method-of-doom from C++, we'd see a SystemError. Aside from removing an
error message, this probably has no effect.
Add isUsed bindings to pySimpleStateVariable

This lets python scripts determine if variables in SDL blobs are used (at
the default).
Move Python string helper to the correct location
Merge pull request #231 from dpogue/fixes

Linux fixes
Manual merge of Pull Request #232 from zrax/plString

Conflicts:
	Sources/Plasma/CoreLib/HeadSpin.h
Remove hsFileStream

It's unused windows-specific garbage.
Merge pull request #233 from Hoikas/py_system_error

Fix Scary SystemErrors
Fix UnifiedTime collision

Win32's GetCurrentTime and plUnifiedTime::GetCurrentTime collided. Rather
than hacking around the solution by undefining GetCurrentTime, we rename
plUnifiedTime::GetCurrentTime to plUnifiedTime::GetCurrent. This fix is
less fiddly than an undef hack.
Refactor avatar movement code

plMovementStrategy classes have been reworked and completely replace all plAvatarControllers.
While based on the old implementation, plPhysicalControllerCore has essentially been rewritten.
Remnants of long gone physical "actions" have been removed.

4 files removed -
plAVCallbackAction.h & plAVCallbackAction.cpp
plAntiGravAction.h & plAntiGravAction.cpp

This revision will not compile, requires new plPXPhysicalControllerCore implementation.
Updated plPXPhysicalControllerCore

While based heavily on the old implementation, this is essentially a rewrite.

Notable changes -
Controllers are now updated at the same fixed frequency as the simulation.
Resulting output is interpolated between steps to precisely match the frame delta.
Physics work is only done when enough time has passed to perform a step.

The kinematic actor that followed around the controller has been removed.
The underlying kinematic actor created by the NxController is now used for triggering.
A new sim group was added for a kinematically controlled avatar.

2 unused files removed -
plPXPhysicalController.h & plPXPhysicalController.cpp
Remove some PhysX workarounds that are no longer required.