major refactoring of scripts (fixing a few issues)
Introduced a new Python-based Domain Specific Language to configure and run the builds. Re-implemented most of the scripts using the new classes.
This patch addresses:
- part of LBCORE-110 (new configuration system for the nightlies)
- LBCORE-572 (update the nightly build dashboard db with the start times of builds and tests)
- LBCORE-559 (extend the nightly build summary pages to show build and test logs of data packages)
- LBCORE-420 (replace the current ctest-based build wrapper with some simpler Python code)
- LBCORE-60 (factor out common code in the new nighlty builds scripts)
- LBCORE-170 (simplify how we specify the slot to be built to the nightly scripts)
It also opens the way to cover several other tasks.