cli: Fix sed message.
Take GL_SAMPLER_BINDING in consideration.

Fixed the issue that GL_SAMPLER_BINDING is only shown globally under
'Parameters' for the last activated texture unit.  We should show
GL_SAMPLER_BINDING for each texture unit.

In this change, we also introduce GL_SAMPLER under each texture unit if
the sampler is bound.

Signed-off-by: José Fonseca <jfonseca@vmware.com>