allow bypassing swauth_manager for single domains

if the pipeline is set up for serving swauth and liteauth from the same domain name and same proxy-server allow requests to bypass swauth-manager if it should not serve these
to allow bypass set up `allow_passthrough = yes` in config file for swauth_manager egg
fix import bug in liteauth.py
Merge pull request #18 from pkit/devel

allow bypassing swauth_manager for single domains