Prepare the building script to suport travis or set other automated
builds, while keeping other options to manual builds.
In before_install script, create needed directories, and dowload
mdbtools sources.
Add smtk2ssrf build script to travisbuild.sh
Signed-off-by: Salvador Cuñat <salvador.cunat@gmail.com>
Previous script would fail on git folders that pull from more than one
repo. That's not a general case, but pretty usual for developers
pulling/pushing to github.
BTW in this cases, a lind git pull doesn't ensure we are pulling from
the right repo.
When run without flag, default to pull --rebase.
At the same time introduce a tiny func to return a message and bail out
after some command failures.
