- updated astyle lib to version 3.6.16
 - added C# Unity language definition (https://gitlab.com/saalen/highlight/-/merge_requests/157)
 - updated RPM spec definition
 - fixed SWIG module compilation
 - fixed Unicode RTF output
 - refactored CMakelists.txt to simplify its structure
 - refactored Makefile to use automatic dependency generation and pattern rules
 - fixed undefined lua upvalue (https://gitlab.com/saalen/highlight/-/work_items/261)
 - C++17 code refactoring