Remove the client generator from Apipie itself

It's hart to make the client code generation generic enough to fit
all the projects (including authentization, versioning etc.).

Therefore, I'm removing the code itself from this gem. Preferred way
is to use the apipie.json data that this gem provides and use that to
generate the code that fits the project needs.

An example of a client generator using the API is here [1]

[1] - https://github.com/mbacovsky/foreman_api
Fixing the doc's reloading in Rails 3.2
Fix test regressions
Merge pull request #74 from iNecas/extract-client-generator

Remove the client generator from Apipie itself
Update cache generation to work with versioning
Merge remote-tracking branch 'origin/master' into versioning

Conflicts:
	lib/apipie/client/generator.rb
	lib/tasks/apipie.rake
Remove unused code
Access _methods through other methods
Add versioning support to extractor and saved examples

Every example apipie_examples.yml now can contain versions key with
array of versions the example is valid for.
Fix functional tests examples recorder return value

When injecting the method for observing request/response, make sure we
return the original value.