* 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
