Fix mysql_db dump and import to use port argument

The code for mysql_db did not pass the port argument when state=dump or
state=import.
Add quotes to password argument for dump/import

The password is passed on a command line for dump and import and needs
quoting.

Ideally, this would not be passed on a command line at all - any ideas?
Or at least have a stronger form of quoting so that embedded single
quotes will be escaped.
Merge pull request #5435 from jkleckner/fix-mysql-dump-import

 mysql_db module: make dump and import to use port argument