Install Ruby mapscript in sitearchdir instead of archdir.
add script for printing out release-notes in rst format
update for 6.4.0 release
restore dev version to 6.5
Merge pull request #4754 from sebastic/ruby-mapscript

Install Ruby mapscript in sitearchdir instead of archdir.
RFC98, RFC99

- implement complex scrit shaping via harfbuzz
- refactor text rendering pipeline
- remove support for GD renderer
- remove support for deprecated annotation layers