Do not force people to use the swift-dispersion node

This role is optional. And people won't be able to assign more than one
node, thanks to the constraint (that is used for validation too).
Merge pull request #236 from vuntz/no-mandatory-dispersion

Do not force people to use the swift-dispersion node
Merge branch 'release/roxy/master' into roxy-sync-again
Merge pull request #237 from vuntz/roxy-sync-again

Merge roxy branch into stoney
Updated routes for rails 4
Added documentation and modified readme
Added gitignore file
Moved i18n file
Added copyright headers and updated files to new rails 4 and ruby 1.9 style
Added magic utf8 token to ruby files
Replaced all route calls
Refactored and restructured barclamp
Restructured controller initializer
Added documentation base file and fixed documentation format
Added missing magic utf8 tokens
Fixed permissions