KAZOO-1104: remove completely useless callflow module
KAZOO-1104: updated specs, formatting, types, etc
KAZOO-1104: ensuring callflow modules only exit after calling a cf_exe method

No module should just terminate silently; should use the cf_exe functions
like continue, stop, etc.

Also cleaned up more specs and types, tickies.
KAZOO-1104: massive sed to replace wh_json:json_object with object
KAZOO-1104: no need to track self in state
KAZOO-1104: add/update types, spec
KAZOO-1104: start to resolve missing functionality
KAZOO-1104: call the appropriate sync function
KAZOO-1104: fix busted rebase, and update specs
KAZOO-1104: removed sysconf exchange declaration as it caused a short-lived queue to be created
KAZOO-1104: updated formatting, added call_id_status helper
KAZOO-1104: update to use integers for numerical data (no reason to encode as binaries)
KAZOO-1104: update dialyzer warnings in conference
KAZOO-1104: updated fax app with spec/types
KAZOO-1104: update some spec and formatting
KAZOO-1104: update spec to include proplist
KAZOO-1104: updated copyright, some tickies
KAZOO-1104: fix log line when using custom options
KAZOO-1104: kill a sub module when terminating cf_exe goes down
KAZOO-1104: add some debugging to see what cf_voicemail is up to