fai-do-scripts: optionally exit on first error.

Adds the option -e to exit on first script error.
Optionally fail task configure on first script.

As a standard FAI runs all scripts and just logs errors. This
introduces FAI_CONFIGURE_RUN_ALL, which will abort fai-do-scripts
on the first script exiting with an error code != 0.
fai-do-scripts: write condensed configure.log

Keeps writing logs to their own script logs but additionally
writes a condensed configure.log for all scripts.
fai-do-scripts: optionally execute unknown scripts

Adds the option -u to execute unknown script types.