Added added glacierwide cumulative balances to areamean.txt; increase array sizes of names in variab.h

purpose: allow comparison e.g. with GRACE time series; no change in
input.txt, column is added to areamean.txt;
Before: mass balance only computed if if( ((winterbalyes == 1) &&
(summerbalyes == 1)) || (maxmeltstakes > 0) ), NEW: if condition
removed.