Building baton or Jansson from source is skipped on upgrade

[Xophmeister]

If baton and/or Jansson's version is bumped, but a previous version is already installed on the host, then the "configure-make-make install" dance will be skipped (and, hence, no upgrade will be done) because it only checks that the binary exists, not what version it is.

• Jansson: Checks for /usr/local/lib/libjansson.so
• baton: Checks for /usr/local/bin/baton