Revert "Core: properly handle Ctrl-C"

This reverts commit 4568c44372c99ba809826e016680da9b881bd8e8.

Trying to handle ^c in the core is difficult and can break STDOUT for
interactive programs that invoke the core.

Signed-off-by: Sol Jerome <sol.jerome@gmail.com>

Conflicts:
	src/lib/Bcfg2/Server/Core.py
	src/sbin/bcfg2-test
	tools/bcfg2-profile-templates.py