Bug 1448: Fixed remaining MAC sources, so that they also compile with the new package-version structure

Created script taqlflagger to easily (un)flag baselines, etc.

Bug 1237: Added (static) maxTime() that returns the maximum time that can be represented in a Timestamp.

Bug 1237: Datamodel of beam split into a base class Beam (= collection of pointings and rcus) and two
derived classes DigitalBeam (+= subbands and beamlets) and AnalogueBeam (+= rank).
Introduced a AnaBeamMgr to manage the analogue beams.
Made several classes printable.

Bug 1453: Removed reversal of azimuth from HamakerDipole, as it seems to be wrong: in the model, positive azimuth runs from the positive x-dipole to the positive y-dipole. Assuming the positive y-dipole is eastward from the positive x-dipole, azimuth runs positively "in the real world" as well.

Added support for clean

Bug 1453: Added tile beam and updated Model class to construct the right expression for LBA and HBA measurements.

Bug 1310: Some program were not being installed because lofar_add_executable() was used, instead of lofar_add_bin_program()

Fixed bug where XY, YX, and YY were not averaged