The FOAM file format has not changed from version 2.0 in many years and so there
is no longer a need for the 'version' entry in the FoamFile header to be
required and to reduce unnecessary clutter it is now optional, defaulting to the
current file format 2.0.
The general distribution has been extended to accept cumulative
distribution data, by means of a "cumulative" switch. The calculation of
the mean value has also been corrected for this distribution, and
additional header documentation and parameter checking has been added.
In addition, the distribution models now all print some basic
information (min, max and mean) into the log file to help in checking
that the specification is correct.
Patch contributed by Timo Niemi, VTT.
