Buffer style fixes
Factor out verify_databases.h
Factor out verify_services.h
Factor out verify_methods.h
Implement automatic discovery and bootstrap for cf-agent.

cf-agent discovers policy servers using Avahi implementation of Zeroconf protocol
at runtime using dlopen.

If a single hub is discovered cf-agent will automaticaly bootstrap to it.

If there's more than one hub discovered cf-agent will print a message listing
available hub and ask user to manualy bootstrap to a proper IP address using
--bootstrap --policy-server <right IP address> command line option.

To use automatic bootstrap --bootstrap/-B command line option is required without
specifying the IP address.
Implement generation of Avahi configuration file.

Add new command line option to cf-serverd -A. cf-serverd executed
with this option will generate Avahi configuration file in
/etc/avahi/services and restart avahi-daemon to make policy server
discoverable over the network.
Register atexit function to close loaded library.
Move include of atexit.h to findhub.c .
Check if avahi is installed on the machine while running configure.
Fix wrong atexit function name.
Enable -A option for cf-serverd only if avahi is installed on host.
Use generic linked list for storing information about found hosts.
Check if two hosts found have the same hostname.
Fix indentations.
Remove unused function isIPv6.