Add the InfNameResolver class

This class allows to do asynchronous host name lookups with support for
SRV records. SRV lookups are only implemented on Linux at the moment.
Add the resolver property to InfTcpConnection

This allows InfTcpConnection to resolve a hostname by itself before it
connects to it, with the advantage that it can try all available
addresses for the hostname in question.
Add support to InfXmppManager for hostname-based TCP connections
Fix a memory leak in InfGtkBrowserView

The browser variable could be leaked in
inf_gtk_browser_view_progress_data_func().
Fix a resource leak in InfUser

The connection object was not released.
InfGtkCertificateManager: Read known hosts file correctly with IPv6 addresses
Fix a memory leak in InfAdoptedUndoGrouping
Fix a memory leak in InfTextUndoGrouping

The behaviour was also not correct, since the function took the position
from the original request, and not from the translated one.
Fix a small typo when creating the serial number of a certificate
Fix compilation of InfGtkPermissionsDialog with GTK+ 2
Initialize libinfinity in inf-test-tcp-connection

So that on Windows WinSock is initialized
Fix infinoted not starting when accounts file is not available
Fix infinoted shutdown procedure on Windows

It is run concurrently with the program, so instead of just shutting infinoted
down (which did not seem to be a problem when InfStandaloneIo could not handle
calls from another thread), now we dispatch a message to the main thread, to
shut infinoted down.
Fix use-after-free in Win32 implementation of InfStandaloneIo