backport of #720 to describe context in exception views

Conflicts:
	CONTRIBUTORS.txt
add removal of ``pyramid.debug_templates`` to "What's New"
Merge pull request #723 from ericrasmussen/1.3-branch

add removal of ``pyramid.debug_templates`` to "What's New"
remove duplicate reference to ``Configurator.scan`` method
Merge pull request #724 from ericrasmussen/1.3-branch

remove duplicate reference to ``Configurator.scan`` method
fix up sphinx config:
  - add correct latex_additional_files so pdf no longer should break
  - add sphinx.ext.viewcode extension
  - make sure the versioning in title, uid is done automatically
  - automatically generate copyright years
  - excluded additional .js files that were stopping epub from generating
    correctly
  - also adjust the remake, make_book, make_epub, make_pdf scripts to use
    env not env27