databases/mysql57-{client, server}: Complete Upgrade of to 5.7.20 (as done by port-secteam in r452458)
Using FreeBSD-ports libcurl and protobuf instead of bundled ones
This upgrade includes:
-Deprecation of these syntax constructs for table and column:
.col_name
.tbl_name
.tbl_name.col_name
-Bugfix of memory-leak in mysqldump

Reviewed by: mat (mentor)
Approved by: mat (mentor)
Sponsored by: Netzkommune GmbH
Differential Revision: https://reviews.freebsd.org/D12712