Update expression runner to use FBco ID as a way of detecting splits

[dosumis]

Line 234 detects whether FBex represents split or not by checking for a comment in the internal processing DB. This finds non split expression
q = engine.execute("SELECT tg FROM feature_expression WHERE comment IS NULL AND tg is NOT NULL")
A similar statement in proc_splits finds splits in the DB.

Proposed Fix: change this to match FBex.uniquename ~ 'FBco.+'

The comment will be null if it does not match the pattern in the original SQL query for FB
L173 "AND fep.value ~ 'when combined with @.@.'"
+ limit)