Andreas Specovius / gammalib

… "xml_has_par" function and made reading of information in observation definition file optional (so that for example energies or ROI can be missing).

The coding and design conventions (CDC) document was also updated.

GTime
  The secs() method now returns a const reference.

GTimeReference
  The load constructor and the read() and write() methods take
  a const reference instead of a pointer.

GGti
  The read() and write() methods now use references instead of
  pointers. The clobber argument in the save() method is passed
  as const reference.

GEbounds
  The read() and write() methods now use FITS references instead
  of pointers. The clobber argument in the save() method is passed
  as const reference.

GPhoton
  Add mcid argument to Photon constructor (defaults to -1).

Add GChatter argument to print() method.

The print() method now takes an argument of type GChatter to control the chattiness of the output in a homogenous manner.
Pass NORMAL chatter level in __str__ method.
Add chatter argument to print() methods.
Use GLog::chatter() method to control the chattiness of the log stream operator.
Add chatter() methods and provide member access through const references.
Add chatter() methods, provide member access through const references, and declare one liners as inline methods.

The chatter() methods control the new m_chatter attribute that is used to control the chattiness of the object's print() methods.
name() and version() methods return const references.
logFileOpen() method now sets the chattiness from the applications's chatter parameter, and name() and version() methods now return a const reference.

The file was corrected so that no more warnings occur during Doxygen documentation generation.

Write the MJD reference into 2 keywords, splitting into the integer and the fractional part, assures the highest accuracy for the reference time. We use this format now as the default, and only write in a single floating point value if the FITS file contains already a single floating point value keyword.

This class implements a time reference.