Added configuration options for TLS cipher suites and TLS versions.

Conflicts:
	src/core/config.xml
	src/core/gen_config.c
	src/core/gen_config.h
Update configs
Potential crash fix for tools.
uhub-admin: don't busy loop before a connection has been established.

This happened due to the network polling mechanism had nothing to poll
for, so it returned immediately only to be called again (during DNS lookup).

This fix introduces a control pipe that is polled for reading, althoug nothing
is ever sent to that pipe. But, it can be used instead of the signal
handler approach which is currently used for terminating the program.
The DEBUG macro never got set, causes verbose log messages to never be compiled in.

Conflicts:
	CMakeLists.txt
Added support for probing HTTP, enough to tell browsers to stop calling.