misc: vppctl - remove the dependency on vppinfra

56f54af21d18f9fdd471b81db77a3942b0aa4d9c introduced the new memcpy.
It also made a vector support mandatory in order to compile anything
that depends on vppinfra.

This broke extras/scripts/build_static_vppctl.sh

Since the vppctl is just a two-pronged epoll+basic telnet client handler,
remove dependencies on the vpp infra libs, and trim the build script accordingly.

Change-Id: I394bc65c485cbf8e7143a818ca0c86367bb15d90
Type: improvement
Signed-off-by: Andrew Yourtchenko <ayourtch@gmail.com>