Revert "channel-main: Convert text line-endings if necessary (rhbz#752350)"
Revert "channel-main: Convert text line-endings if necessary (rhbz#752350)"

This implementation assumes that the toolkit doesn't do any conversion
on its own. This is actually not the case, gtk+ converts line endings
already on windows.  It would be pretty ugly to do conversions back and
forth at different levels. So the channel implementation shouldn't
try to do conversion, and implementation must be done at higher level,
where the actual system clipboard implementation is known (at
gtk-session for instance)

Since this code hasn't been officially released, let's revert it and
implement a better crlf conversion handling in gtk-session in the
following commits.

This reverts commit e45a446a9981ad4adaeff9c885962a8c6140333e.

freedesktop-unofficial-mirror/spice__spice-gtk,fgouget/spice-gtk,fgouget/spice-gtk,freedesktop-unofficial-mirror/spice__spice-gtk,Fantu/spice-gtk,elmarco/spice-gtk,Fantu/spice-gtk,guodong/spice-gtk,guodong/spice-gtk,SPICE/spice-gtk,SPICE/spice-gtk,fgouget/spice-gtk,elmarco/spice-gtk,elmarco/spice-gtk,guodong/spice-gtk,freedesktop-unofficial-mirror/spice__spice-gtk,flexVDI/spice-gtk,SPICE/spice-gtk,guodong/spice-gtk,Fantu/spice-gtk,SPICE/spice-gtk,flexVDI/spice-gtk,elmarco/spice-gtk,freedesktop-unofficial-mirror/spice__spice-gtk,Fantu/spice-gtk