do not check unsigned windowsize for < 0
collapsing duplicate branch
reducing scope of loop counters, and micro-optimising loops by using != where safe and pre-increment wherever return value is not used
optimisation: replacing all unnecessary post-increments and post-decrements with their pre-increment and pre-decrement equivalents wherever the return value isn't used
oops, typo fix
another typo fix
using size_t iterator when comparing to size_t
Merge branch 'master' of https://github.com/lvandeve/lodepng

# By Lode (10) and others
# Via Lode
* 'master' of https://github.com/lvandeve/lodepng:
  fix for C
  fix examples
  better bitpointer checks
  small tweaks
  Update lodepng.h
  Update lodepng.cpp
  avoid too big pixel sizes
  predict idat size correctly for interlaced images
  unit test was a bit slow like that
  fix bug with encoding transparent single-pixel image
  protect against invalid chunk lengths in some tools
  fix pngdetail.cpp
  collapsing duplicate branch
  do not check unsigned windowsize for < 0

Conflicts:
	lodepng.cpp
fixing preincrement bug introduced previously
more != comparisons instead of < against unsigned types for loops starting with 0
ensuring ANSI C compatibility by using ifdefs where appropriate
Merge https://github.com/lvandeve/lodepng

# By Lode
# Via Lode
* https://github.com/lvandeve/lodepng:
  various fixes

Conflicts:
	lodepng.cpp
Removing all C99 version define switches and the associated C99 functionality
Merge branch 'ansi_c_only' of https://github.com/slowriot/lodepng into slowriot-ansi_c_only
tiny tweaks