Corrected mapping bug in mdtSqlFormWidget
Working on field map

In mdtFieldMap, the several hash that acted on a copy of items list are now removed.
It was too complicated and dangerous to keep so many containers up to date.
Now, searching is done by for() loops, but this seems not significantly slower
 for the number of items (10, maybe 100 for grate tables).
Working on field map: created map item dialog + some corrections