1.3 (2015-06-12)

• Added a OpenGL/GLFW user interface in duc guigl, which can be used as a native UI for Mac OS.
• Duc CGI no longer depends on cairo/pango. Good for headless servers and embedded file servers.

Detailed changes from the previous version:

- new: added SVG and HTML/canvas graph back ends
- new: added OpenGL/GLFW graph back end for better portability
- new: added tooltip to CGI, enable with --tooltip option
- new: duc database is now portable between endianess and
       architectures for sqlite3 databases
- new: added --ring-gap option to gui
- new: added --color option to ui
- cha: optimized memory usage
- fix: fixed building on Solaris
- fix: added better error handling in sqlite3 backend