robustness: ensured that stuff works even if there is no revision file
Early (non-functional) draft for a LUA survey phase
worked on implementation transfer

All this stuff is merely "copied" from the TeX sources, no significant refactoring
worked on point meta reimplementation in LUA
lua lib: added support to call parent constructors
worked on initial LUA backend draft
fixed lua bugs
Prepared tex code for lua backend activation
first LUA survey which produced useful log messages
TeX survey acquires results from LUA backend: first draft
added code comments
added first draft of a LUA backend for point meta mapping

This speeds up things considerably for surface plots.

Note that it is only available for plots which have been surveyed by LUA (for now)
Moved LUA code to initialize plot handler to an earlier spot
added LUA backend for (simple) z buffer implementations
Merge branch 'master' into luabackend

Conflicts:
	tex/latex/pgfplots/pgfplots.sty
refactoring
refactoring
added additional switches to disable the lua backend if needed
Added additional properties for LUA backend + improved logging
code cleanup