fix building on F18

addressing several problems.
compass compile is dissabled because of
https://github.com/rails/sass-rails/issues/121

apipie is disabled because it tries to connect somewhere and fails to connect
Fix F16,EL6 after fixing F18
correctly compare version
do not fail if you use bundler

if you do not have compass gem available, you must be using "bundler install"
In such case make sure that you will use compass > 0.12.0.
Otherwise determine what version of compass you have and require compass-rails if needed.
workaround BZ 901540
do not use ZenTest 4.8.4

addressing:
324RUNNING: RAILS_ENV=development bundle exec compass compile

325Invalid gemspec in [/home/travis/.rvm/gems/ruby-1.8.7-p371/specifications/ZenTest-4.8.4.gemspec]: Illformed requirement ["< 2.1, >= 1.8"]

326sh: 1: rpm: not found

327Invalid gemspec in [/home/travis/.rvm/gems/ruby-1.8.7-p371/specifications/ZenTest-4.8.4.gemspec]: Illformed requirement ["< 2.1, >= 1.8"]

328Invalid gemspec in [/home/travis/.rvm/gems/ruby-1.8.7-p371/specifications/ZenTest-4.8.4.gemspec]: Illformed requirement ["< 2.1, >= 1.8"]

329sh: 1: rpm: not found

330Invalid gemspec in [/home/travis/.rvm/gems/ruby-1.8.7-p371/specifications/ZenTest-4.8.4.gemspec]: Illformed requirement ["< 2.1, >= 1.8"]
Merge pull request #1418 from xsuchy/pull-req-f18-3

fix building on F18