mongo_db_data_storage improvments + mongo exceptions management
removing saving files
adding MongoClient class test for mongo connection options
adding  parameter in get_connection function
create function returns mongoId now
add and _save functions throw an exception if we try to create a document with empty forced uid
add function returns mongoId now
add function uses Mongocollection insert function now
exception management improvment
mongodb_data_storage phpunit tests
removing tmp file
Merge pull request #37 from lutholea/feat/vb/mongodb_datastorage_improvments

mongo_db_data_storage improvments + mongo exceptions management