Braces for ifs.
Fix incorrect comparison and signedness warning.

Stack locations of 0 are valid.
Replace preprocessor with standard conditionals and enums.

It's an enum, so I can probably assume the compiler will kill the code
if it's always false.
Remove use of invalid bitmask code in call_function_nt.

No longer valid. Also, call arguments go on the stack -- always -- now.
Remove unused code.
Reverse host callback argv values.

Since arguments are pushed onto the stack in reverse order.
Rather than reserve, just resize.
Remove old, unused config macros.
Default vm_state_t stack size to 8192 values.

May as well go large.
Update build script and test program source.

Currently just testing the unit loader.