fix warnings and removed some asserts

* removed lastAttemptedSubTree variable in octree server since we aren't using it.
* changed a bunch of asserts to debug messages since they produce warnings on unix and because the warning messages are a more graceful failure.
* fixed ByteCountCoded<> which was using T when it should have used int
* fixed lots of signed/unsigned warnings through the code
* fixed a couple of floats not properly defined warnings on windows
* fixed an uninitialized variable warning in MetavoxelSystem.cpp
* fixed a couple of truncated values warnings
* fixed an accidental bool that should have been an int in PropertyFlags<Enum>:
That's correct; the initialization isn't necessary, because lastIndex isn't used for the first iteration (x == 0), but adding it to suppress the warning is fine.