[dev] Added global Rakefile and required adaptations of existing scripts.

README.md

Rakefile

generators/input-validators/check-cluster-homogeneity.rb

generators/input-validators/yaml-input-schema-validator.rb

generators/lib/input_loader.rb

generators/puppet/conmang5k.rb

generators/puppet/dhcpg5k.rb

generators/puppet/kadeployg5k.rb

generators/puppet/lanpowerg5k.rb

generators/puppet/templates/bind-global-site.conf.erb

generators/reference-api/reference-api.rb