retrieve the user who suggested a candidate
retrieve item for candidate ID and vice versa
Rename + Add methods

Two methods for existence-checking: one by candidate ID,
one by item ID. Adjust create.php to use the one by item.
add checks in case a candidate is not found
Add DB column and method for approval
implement method for acception status retrieval
add a method for checking if candidate has been approved
Add missing config file required for Candidate::accepted()
Begin API method for candidate approval
implement StdlibPending::AddEntry()
Use new StdlibPending method when a candidate is accepted and approved