- Fail early if gem install fails
This avoids confusing error messages at the end of the build.

- More fixes for ruby 1.8

- Ruby 1.8 insists on the () for the parameter

- Cleaner solution for the extensions doc dir
The other solution was also failing on 1.8

- Forgot another option for forwarding

- Do not overwrite options.otheropts

- Fixed forwarding of options to gem install

- Only use the extensions doc dir on MRI 2.1.x

- Fix the ruby suffix for distributions before 13.2
- Do not fail with --gem-binary

- switch to ruby version of gem_install.sh
- added ruby-find-versioned to make it easier to find versioned
binaries.
- all for loops in the shell scripts and macros are now using
this script