Regex behavior in Falko metadata is incorrect

When searching for regex in annotations, it is assumed the user means an initially and finally anchored string, i.e. the query

tok=/[Uu]nd/

is actually looking for the expression /^[Uu]nd$/. As a consequence, this query does not find "Hund". This is correct.

In metadata, this does not happen correctly. Looking in FalkoEssaysL2, this query:

tok & meta::l1_1=/[^e].+/

finds texts with l1_1="eng", because "eng" contains [^e].+ as a substring: the "ng" part. This query should also be treated as looking for l1_1=/^[^e].+$/, so that metadata and annotations behave in the same way.