- dirmngr/cdb.h (struct cdb): Remove mapping handle.
- dirmngr/cdblib.c (cdb_init): Read file into mem on windows.
(cdb_free): Free mem for Windows.
This fixes the problem that dirmngr keeps open handles to
the CRLs and flush / delete of the GnuPG Home Directory
does not work.
For Windows we can assume that memory for CRLs is available
and we don't have to optimize for memory usage here.