Added more tests.
Handle empty prerelease/metadata in X-ranges.
Added incrementers/decrementers.
Removed support for prerelease/metadata in x-ranges.
Initial XRanges converter.
Added rewind method.
Add checking of item value to tests.
Removed code that is not needed with new lexer output.
Show function name in debug information.
Added more x-range tests.
Fixed XRange lexing.
Prevent emiting hyphen item is not followed by whitespace.