- fix issue4819
- modify polygon render to exclude consectuvie points that are less than
  a pixel appart
- moved inner loop debug prints to level 3 and 4 since they where
  slowing down too much the code in debug
Merge branch 'issue4819' of github.com:Oslandia/Quantum-GIS into issue4819

Conflicts:
	src/core/qgsdistancearea.cpp