deprecation of Silverpeak generator

[vklimovs]

Hi,

Maintenance of silverpeak generator (https://code.google.com/p/capirca/source/browse/trunk/lib/silverpeak.py) has become increasingly burdensome for Googlers who develop capirca. Due to that and the fact that we do not have use for generator anymore, we plan to deprecate the generator and remove the code. I will do that in a week if there are no objections.