OpenSCAD 2011.04

• Added hull() for convex hulls (2D object only)
• minkowski() now supports 2D objects
• Added functions: rands(), sign()
• Now supports escaping of the following characters in strings: \n, \t, \r, , "
• Support nested includes
• Improved parsing of numbers
• DXF: output LWPOLYLINE instead of just LINE entities
• Bugfixes: More robust DXF export, setting $fs/$fa to 0 caused a crash
• Some bugs fixed, maybe some new bugs added