include dialog_examples.so in mariadb-server packages (Ubuntu)

I've been getting a few client libraries up to date to current server capabilities.

Having dialog_examples shared library included, in for example the server packages, would enable this to be easily enabled in travis-ci builds of client libraries (e.g. CONJ-164).

While the pam plugins also used the dialog, enabling the two question/three attempts modules in sql example provides something that is easier to configure in a root limited access build and provides better test of client capabilities than basic username/password.

ubuntu 12.04/14.04 are the main targets I'm interested in as these are what Travis-CI uses.