devel/buildbot*: Update to 0.9.11, Add buildbot-grid-view

• Update to buildbot 0.9.11
• Add required devel/py-buildbot-grid-view dependency
• Clean up stuff from individual Makefiles that was copy/pasted from the main buildbot Makefile
• buildbot-www, buildbot-grid-view, buildbot-console-view, buildbot-waterfall-view cannot be tested outside of buildbot, so remove stuff from their Makefiles to simplify.

Reviewed_by: koobs, asomers, sunpoet
Approved by: grembo
Differential_Revision: https://reviews.freebsd.org/D12479