move host and domain from xsce.yml to default_vars.yml
reorg default_vars.yml
add install and enable flags for each role
make each role conditional in meta/main.yml
standardize on True/False
squid to squid_enabled
dansguardian to dansguardian_enabled
more name changes
add set of enabled True flags for testing
Merge pull request #177 from tim-moody/install-enable

Implement New Install and Enable Flags - Part I