Added basic key/value search

Containers are recursively searched for given keys or key/values. 

/operations/container/list/<starting container>?recursive=true&key=X
will return a list of containers with matching keys

/operations/container/list/<starting container>?recursive=true&key=X&value=Y
will return a list of containers with matching key/value paris

/operations/container/content/<starting container>?key=y
will return the contents of all containers matching the given key

/operations/container/content/<starting container>?key=X&value=Y
will return the contents of all containers matching the key/value pair