Port PPeg to LPeg 1.0

[moreati]

PPeg is currently based on LPeg 0.9 (released in 2008). The current release is LPeg 1.0, which includes the following changes

• Changes from version 0.12 to 1.0
  • group "names" can be any Lua value
  • some bugs fixed
  • other small improvements
• Changes from version 0.11 to 0.12
  • no "unsigned short" limit for pattern sizes
  • mathtime captures considered nullable
  • some bugs fixed
• Changes from version 0.10 to 0.11
  • complete reimplementation of the code generator
  • new syntax for table captures
  • new functions in module 're'
  • other small improvements
• Changes from version 0.9 to 0.10
  • backtrack stack has configurable size
  • better error messages
  • Notation for non-terminals in 're' back to A instead o
  • experimental look-behind pattern
  • support for external extensions
  • works with Lua 5.2
  • consumes less C stack
  • "and" predicates do not keep captures

Thank you for this awesome work of maintaining this library. LPeg is fantastic and is one of the most important thing I miss in Python !