[2.0] Internal Updates

[rtheunissen]

• Embed structures in their php_ wrapper rather than a pointer to them. See Embed structure members directly, rather than allocated separately. #40
• Consider only allocating buffers when they're needed. See Consider only allocating internal buffers when they are needed #61
• Make sure that all functions, constants and macros are namespaced.

[rtheunissen]

This is now outdated.