[utils] Added new get method to QueryCache
The new get method enables the retrieval an item in the cache by specifying a
default value so that in the absence of an item for the key, the default value
is returned.
missing-dep-for-interpreter make => make | build-essential | dpkg-dev (usr/*/cubicweb/skeleton/debian/rules)embedded-javascript-library usr/share/cubicweb/cubes/shared/data/jquery.js