add yet another selectbox plugin.
ZMySQLDA: attach connections to ZODB connections instead of threads

This makes code simpler, faster and easier to understand.
It is easy to forget that ZODB connections can be reused by different threads,
which led to bug such as the one fixed by commit 2c11b76.

ZODB already maintains a pool of connections to reuse
so we don't need anymore to have one.
ZMySQLDA: fix condition to detect disallowed multiple select schema
ZMySQLDA: code cleanup
ZMySQLDA: accept 'db@unix_socket ...' syntax for connection strings

This deprecates the old syntax, which uselessly requires to specify credentials.
Merge ZMySQLDDA product into ZMySQLDA
tests: reuse ZMySQLDA parser to build arguments for 'mysql(dump)' command line

This adds support for IPv6 and new syntax for unix sockets.
Merge remote-tracking branch 'origin' into aurel-stock-cache
fix script to install bt5 from repository

it should not be based on it but on title to check dependencies
if only provider is possible, use it
wrap long lines

Conflicts:
	product/ERP5/bootstrap/erp5_core/bt/revision
Merge remote-tracking branch 'origin' into aurel-stock-cache