Fabio Iocco / ctools

So far any exception occuring during the construction of the ctools were not catched. This is corrected now.

The ctool::get_roi() replaces some duplicated code in ctselect and ctcubemask. The method extracts the RoI from the user parameters "ra", "dec" and "rad". In case the "usepnt" parameter is present and set to "yes", the "ra" and "dec" parameters will not be read, and it's up to the client to set the RoI centre properly.

Since the new GApplication logger methods are more compact than the old format the "logTerse()" etc. constructs have been replaced by the new logger methods. At the same time, the chattiness levels have been reviewed with the following behaviour:
- TERSE: only headers
- NORMAL: standard output, only main results or computations
- EXPLICIT: detailed output
- VERBOSE: verbose output, mainly for diagnostics

The GCTAEventCube::map() method has been renamed to GCTAEventCube::counts() (#1789)

The publish parameter has been added to the following tools:
- ctbin
- ctbkgcube
- ctcubemask
- ctexpcube
- ctmodel
- ctskymap
- cttsmap

… ctcubemask for this purpose

…)-function of individual ctools

…d scave() methods to ctool interface. Add read_ahead() method to handle reading of task parameters at the beginning of the task execution. Remove all m_read_ahead members from the derived classes.

* Checked the code for coding conventions.
* Renamed the angular seperation user parameters to amax and anumbins. "a" stands for angular separation, "d" for delta is less explicit.
* Add ctpsfcube executable unit test