changes for config subsystem - BUG 754

integration - issue with initialization pending
added sal generator
changed SPI - SwitchConnectionProvider has 1:1 bound with ServerFacade
extended yang model of SwitchConnectionProvider configuration
restored exported packages for osgi
restored documentation generator
changed API in order to use ListenableFuture instead of plain Future

Change-Id: Ic21e3a0c1fd64584d98485567c26095674291548
Signed-off-by: Basheeruddin Ahmed <syedbahm@cisco.com>
Signed-off-by: Michal Rehak <mirehak@cisco.com>
(cherry picked from commit cbe4871cddf78adab335b5270269b6e704eb8bf9)