Rename block_device.rb ohai plugin to block_device_extended.rb

Otherwise, it just doesn't work.
Merge pull request #202 from vuntz/fix-ohai

Rename block_device.rb ohai plugin to block_device_extended.rb
Added documentation and modified readme
Added gitignore file
Moved i18n file
Removed unsed build files
Removed prereq cookbook and wsman as it is not used anywhere
Cleaned crowbar configuration
Updated copyright header
Added magic utf8 token to ruby files
Restructured controller initializer
Added documentation base file and fixed documentation format
Reafctored most parts and did some unification