one small step further to generating batch requests, that are accepted by arangodb
change names of clojure idiomatic methods to avoid name conflicts with clojure.core methods
add query namespace and method prototypes and docstrings 'explain' and 'validate'
implement query/explain and query/validate
query/explain can take a db name now optionally or uses default database
rename methods filter-out-collection-name-from-args and filter-out-database-name-from-args: remove the '-from-args' part