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>