Small change to trigger a readthedocs rebuild.

Somehow the mapcrafter.png image does not work.
Adapted documentation for new configuration file format.
Fixed small typo.
Fixed lighting of new stairs.
Fixed rendering of stained glass panes.
Made stained glass display properly.
Added piwik to readthedocs docs.
Fixed block in template for piwik script.
Sphinx documentation test to detect readthedocs environment.
Fixed not rendering glass because of small typo.
Merge branch 'master' of https://github.com/m0r13/mapcrafter
Added cobblestone walls as fences with cobble textures for now.
Fixed not rendering jukebox and also its orientation.
Trying to use piwik code in 'linktags' block
Added forgotten acacia/big oak wooden planks.
Piwik should work now with readthedocs theme.
sphinx conf.py configuration for buildbot.
Url mapcrafter.readthedocs.org => docs.mapcrafter.org
Moved implementation code to source files.
Added Image::resizeAuto which chooses optimal interpolation type.
When increasing image size it's better for Minecraft textures to use the
nearest neighbor interpolation rather than the bilinear interpolation.