Revert "Add basic discovery API."

This reverts commit 1de047192e8d626f251dc07767112f4d4ae343b2.
NSD: Base implementation of NSD within WebCore

Conflicts:
	Source/WTF/wtf/FeatureDefines.h
NSD: Adding discovery providers (UPnP and ZeroConf)
NSD: Update WebKit Build to compile NSD

Source WebCore build change

Conflicts:
	Source/WebCore/CMakeLists.txt
	Source/WebCore/DerivedSources.make
	Source/WebCore/GNUmakefile.am
	Source/WebCore/GNUmakefile.list.am
	Source/WebCore/PlatformEfl.cmake
	Source/cmake/WebKitFeatures.cmake
	Source/cmakeconfig.h.cmake
	Tools/efl/jhbuild.modules
NSD: Qt build support
NSD: Qt build fixes

Since QtWebKit 5.2.1 is based on a very old WebKit trunk revision some
changes needed to be adapted in the NSD implementation to make it build.
NSD: general build fixes

Fixed 2 include statements and added a stdio.h include in the Avahi
backend, needed for sprintf().
NSD: [Qt][WK1] basic NetworkServicesClient

Some methods are not implemented because the corresponding port
top-level API is missing too.
NSD: [Qt][WK1] Implement ::notifyDiscoveryFinished()
NSD: [Qt][WK1] HACK: unconditionally allow access to services

This is a temporary workaround. Ideally the browser will ask the user
permission before accessing discovered services. A white-list system
could also be set up.