This commit adds a default timeout of 10 seconds to the rule engine's
`jq/2` function, and adds a new function `jq/3` (where the last parameter is
a timeout value). The default timeout can be configured with the setting
"rule_engine.jq_function_default_timeout".
Having a timeout when executing jq code in the rule engine is important
as jq code can potentially run forever. Also, the Erlang jq library
limits the number of jq programs that can execute concurrently so a jq
program that loops forever could potentially also prevent a "non-buggy"
jq program from ever starting.
Shawn