Enable static linking with Mysql and Postgresql libraries for Sphinx.

Signed-off-by: Daniel (dmilith) Dettlaff <dmilith@verknowsys.com>
Added explicit info about libraries location for Sphinx static linking.

Signed-off-by: Daniel (dmilith) Dettlaff <dmilith@verknowsys.com>
Try static linking only for Mysql.

Signed-off-by: Daniel (dmilith) Dettlaff <dmilith@verknowsys.com>