The functions we have in that library so far are only usable in conf mode. In op mode, they do not work (and in fact cause cli-shell-api to segfault, but it's a different story). This makes the library unusable for op mode scripts.

We need to add the following cli-shell-api functions to it:

• inSession
• returnEffectiveValue
• returnEffectiveValues
• listEffectiveNodes
• existsEffective

in_session should take no arguments and return a bool (cli-shell-api inSession exists with 0 if true and >0 otherwise).
The rest should behave as their non-effective counterparts.