New startup and echo_env scripts

Redesigned echo_env and startreflect to cope with situations where a channel may be misconfigured due to a typo in echo_config, or where the integrated conference configuration may be invalid (missing echo_env, or missing tbd.conf/tlb.conf, or non numeric port value). In these instances, the system will revert to using sfreflect for the channel. The checks aren't perfect, but should catch a number of common issues.