Some fixes, optimizations and cleanups.
Fix incorrect output from esmtool on architectures where plain chars
are signed. Compare incorrect and correct SCPT bytecode dumps
(Script Data Size: 39):
    ByteCode: 060101092058FFFFFFF010203D3D2031FFFFFFCC100F42325F4168656D6D7573614B696C6C0100FFFFFFFFFFFFFFFF09010101
    ByteCode: 060101092058F010203D3D2031CC100F42325F4168656D6D7573614B696C6C0100FFFF09010101
Convert floating-point byteswapping functions in endianess.hpp to macros.
Remove unused 'float mHeightOffset' field from LandData (loadland.hpp).