- got rid of addition of 1 to year - so year reflects end year in yearly output (from SVN revision 327)
- Fixed bug where litter is accumulating but not decomposing in non grow mode.
  (from SVN commit 328)
- fixed bug in DON litter decomp and changed output routines so that an nbalance can be computed
  (from SVN revision 329)
- added routing of NH4 (from SVN revision 330)
- added N-fixation - turned off unless optional stratum default parameter (epc.nfix is set to 1)
 (from SVN revision 331)
- added in PH scalar on nitrification estimation (from SVN revision 332)