This is a stable feature release.

Notable changes:

- Introduce hash table improvement (by Vladimir Makarov)
- Binding#irb: Start a REPL session similar to binding.pry
- Unify Fixnum and Bignum into Integer
- String supports Unicode case mappings
- Performance improvements
- Thread#report_on_exception and Thread.report_on_exception changes
- Thread deadlock detection now shows threads with their backtrace and dependency
- Support OpenSSL 1.1.0 (drop support for 0.9.7 or prior)
- ext/tk is now removed from stdlib Feature #8539
- XMLRPC is now removed from stdlib Feature #12160

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>

ruby subpackages now are generated by a macro. This reduces the
Makefile size by half and the chance of errors.

No change in packages contents, install-size or dependencies, except
for some removed doc files.

Improved ruby_missingfiles and ruby_find_pkgsdeps script

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>

ruby_find_pkgsdeps: look for file dependencies (checks
require and Encoding references) and extrapolate it to pkgs
deps. Also checks whether a dep is redundant or missing in pkgs.
Must run inside an OpenWRT with all ruby* pkgs installed.

ruby_missingfiles: list files in staging/target and from files
comparing side by side its contents. It helps to easly visualize
which file is not packaged in an ipk.

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>