add bindings for 'erode'
add bindings for gaussianBlur
add bindings for arcLength in contours
add bindings for approxPolyDP in contours
add bindings for isConvex in contours
add bindings for cornerCount (size in OpenCV) in contours + fix bool instead of double in approxPolyDP
add bindings for boundingBox in contours --> returns an (x, y, width, height) object
Merge pull request #29 from jtlebi/master

New bindings