Removed the option to not-cache the database schema from the library.

There is no valid reason not to cache the database schema for a ovsdb connection once it is learnt once.
The schema can never change after the connection is established & hence having this dynamic capability is
unneccessary and causes unncessary API confusion.

Change-Id: If147d90a1070beaf85a3d7f9f7f844d73d53acb0
Signed-off-by: Madhu Venugopal <mavenugo@gmail.com>