Gersemi

Added
- support for new keywords in native commands available in CMake 3.20

Changed
- when input is provided through stdin `gersemi` will look for configuration file in current or any of the parent directories instead of only current directory

Fixed
- on Python 3.6 sqlite related TypeError isn't raised anymore

Added
- information about formatted files is cached so that subsequent runs can avoid processing already formatted files
- support for commands introduced between 3.16 and 3.19 releases of CMake

Changed
- minor change to how OUTPUT argument in file(GENERATE) is formatted

Added
- minor performance improvements
- support for Python 3.6

Changed
- files are taken as input only once even if provided multiple times
- files are no longer overwritten if reformatting wouldn't lead to change of content
- removed dependency to `packaging`

Added
- some performance improvements
- relaxed dependency to lark so that 0.9 can be used as well
- loading configuration from `.gersemirc` but command line arguments still take precedence
- colorized diffs with `--color`

Fixed
- comments no longer interfere in splitting arguments by keywords which led to undesired formatting (1)