To enable the clipboard for a VM, add the following node to the
<Hardware> sub node of your machine.vbox configuration:
<Clipboard mode="Bidirectional"/>
Issue #3437
The pthread API is considered a standard feature of libc so better to
simply merge it with the libc. Pthreads are in fact already a part of
the libc in the form of weak symbols. This merger is also a prerequisite
for better integrating pthreads with the libc I/O task.
Fix#3054
