Log Message:
Update to 1.10, set LICENSE.

August 19, 2011: Release 1.10

 A DXF backend was added. The output is in the drawing interchange
 format used by computer aided design software. Thanks to Jonas
 Benedett Dorr for testing. The Gimppath backend was changed to be
 compatible with current versions of Gimp. The EPS, PDF, and SVG
 backends now use high-resolution bounding boxes. The default scaling
 of the EPS, PDF, and SVG backends is now fixed at 72dpi. A new option
 --flat was added to the SVG backend. A new option --tight was added
 to remove whitespace around the input image before calculating its
 scaling and placement.

December 21, 2010: Release 1.9

 The xfig and eps backends were improved, and a fixed pagesize PDF
 backend was added. Support for BMP version 4 and version 5 files, as
 well as top-down BMP files, was added. Minor speed improvements to
 Potrace and major speed improvements to mkbitmap. A Gaussian blur
 option was added to mkbitmap. Libtool is now used to build and
 optionally install the Potrace library. An optional simplified
 progress bar was added for dumb terminals. This release also contains
 some portability improvements, cross-compilation improvements, and
 minor bug fixes.