Pcbnew, export Solder masks in Gerber Format: fix not working export when the solder mask minimal width is not 0 (the exported shapes were the same as if the vule = 0) with boost version >= 1.56
This is due to the fact the boost::pylygon function resize ( a inflate/deflate function) used for calculations does not work with boost version >= 1.56.
Use Clipper  inflate/deflate function instead. It is faster and works fine.