2.5.0 introduces many new features and performance improvements.
See: https://www.ruby-lang.org/en/news/2017/12/25/ruby-2-5-0-released/

Packaging changes:
* As date was promoted into a gem, ruby-datetime
  was splitted into ruby-date and ruby-time
* New packages for gemified stdlib files:
  - ruby-cmath (from ruby-math)
  - ruby-date (from ruby-datetime)
  - ruby-etc (from ruby-misc)
  - ruby-fcntl (from ruby-misc)
  - ruby-fileutils (from ruby-filelib)
  - ruby-ipaddr (from ruby-socket)
  - ruby-scanf (from ruby-misc)
  - ruby-stringio (from ruby-misc)
  - ruby-strscan (from ruby-misc)

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

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>

Signed-off-by: Stefan Weil <sw@weilnetz.de>

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>

For ruby changes since 2.1.x:

 https://github.com/ruby/ruby/blob/v2_2_0/NEWS

Relevant changes for OpenWRT:

* all patches for ruby-core where merged upstream and
  they are not needed anymore (only rdoc patch remains)
 - PR for the rdoc github project was added to the patch header
   (https://github.com/rdoc/rdoc/pull/340)
* new package ruby-powerassert for introduced new bundled gem power_assert
* new package ruby-unicodenormalize for Unicode normalization files
* removed ruby-dl as DL was removed after being deprecated
* ruby-{minitest,testunit} where removed from ruby library. Now they
  are bundled gems
* test and sample files where removed from gems in order to save resources
  and reduce pkgs dependencies
* script ruby_find_pkgsdeps was updated to match upstream changes

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>