Adds two extra shell scripts, one to handle either the c-shell
or bourne-shell syntax for setting environment variables, that can
be sourced in order to set the BROPATH directly in the current
shell/environment in a way that's compatible with running bro
from the build/ directory.
- Added 'dist' target to top-level Makefile for doing source packages
- Added 'make-*-packages' scripts for generating binary packages
- Fixes for the ConfigurePackaging CMake script
- No longer fails when package version doesn't include a patch-level
- Now considers the case when a package doesn't install any
config files and the INSTALLED_CONFIG_FILES var is empty
