Kill global VINPUTFILE, with fire

Leaving global MINUSF intact for now, may need to be wrapped up in some
context object.
Merge pull request #298 from sigurdteigen/cleanup/remove-vinputfile

Kill global VINPUTFILE, with fire
add canonify() to some handle promises to prevent cf-promises FATAL error about invalid rvalue
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.
Check if avahi is installed on the machine while running configure.
Use generic linked list for storing information about found hosts.
Check if two hosts found have the same hostname.
General code cleanup.

Remove unused function isIPv6.

Remove unused structure.

Fix definition of HostProperties structure.

Move PrintList function to public header.

Remove unused definitions of functions.

Replace printf functions with CfOut.

Fix indentation.

Remove error string from CfOut messages.

Remove unused variable 'tried'.

Change output type from cf_inform to cf_reporting.

Code cleanup.