Release version 2.0

• Migrate to Proj API version 6. Tested with Proj 8.0.1
• Modernize CMake
• Use Proj CMake modules to search library
• Fixed issue with POLYGON line generating: POLYGON must be ended with start point.

Full Changelog: v1.0...v2.0

Release version 1.0

• Complete croping algorithm. Need to be checked on map sheets over 60 degrees.
• Move to CMake build system (88387f2).
• More options togdalwarp can be bypassed (6486c16).
• Generate only cutline info without gdalwarp execution. Useful for scripting (038c445).
• Support user-specified output format. More useful now is a VRT one (e67a9e4).
• Support for the World files references: now .prj file can be loaded automatically or specified via command line argument (3eae0f9).
• Translate all message to the English and mostly comments too :-) (e67a9e4, 31208fd)