Till now we have been building against a previous built of subsurface.
This was handy and fast, but there is a huge drawback in this approach
because we were including a lot of unneeded dependencies (e.g. marble
or serial-ftdi), some of which are, indeed, optional.
With this patch, a stripped down version of susbsurface is built and
used to link in smtk2ssrf.
The bad news are that this - almost unusable - version of subsurface
overrides any preexisting binary, so the user has to rebuild.
Signed-off-by: Salvador Cuñat <salvador.cunat@gmail.com>
