add system gem
add countries_for_index and region_for_index
make Search::Index work with simple arrays
add Search::ParallelIndexer
Merge branch 'elastic-search' into es-parallel-indexing

Conflicts:
	lib/modules/search/index.rb
	lib/tasks/search.rake
remove unneded require statements
move indexing in Search::Index.index_all and add drop method
use drop method in finaliser and rake task
Merge pull request #95 from unepwcmc/es-parallel-indexing

Elasticsearch parallel indexing