Remove image caching from Deployable model

The caching was added because the image details were queried from ImageWarehouse over HTTP. With TIM, it's all stored in DB, so no need for this kind of caching.
remove hooks: unfinished and probably obsolete hook controller, model, tests, views
Merge pull request #417 from ifarkas/catalog_image_cache

Remove image caching from Deployable model
Merge pull request #421 from martinpovolny/remove_api_hooks

remove hooks
FK: add foreigner to Gemfile
add Gemfile.lock with foreigner
add foreign keys for catalog_entries
add foreign keys for catalogs
add foreign keys to deployables
add foreign keys for pool_families
add foreign keys for pools
add foreign keys for pool_families_provider_accounts
add foreign keys for hardware_profiles
Merge pull request #400 from martinpovolny/fk-part1-round2

foreign keys part one round two
Gettext conversion - last t-keys (with count and interpolation)
Updated PO/POT files
Move configuration of Gettext

Moved Gettext config from application.rb to initializers/fast_gettext.rb
and added default available languages.