settings to conf file
watermark_position moved from WatermarkEngineBase to conf/defauls
mark cropping
engine methods renamed for to specificate marks methods (cause we mix with thumb)
common methods moved from pil to base engine
The blank _watermark method added to the basic engine
pgmagick engine base
pil renamed to pil_engine README updated
new lines added/docstrings fixed
pgmagick _reduce_opacity docstring fixes
new defaults
default engine note added to README
deleted watermark engine autoinit
README fixed
Merge pull request #17 from vbazhin/master

move settings to conf file and fix watermark placement (fixes #12 #4)