S.Hem pheno

[mdekauwe]

Currently doesn't work

• Added logic to calculate leaf on/off dates
• Added logic to calculate transfer fluxes respecting s.hem growth

Outstanding Issues:

• in gday.c things are being zero'd at the end of the year which is of course the middle of the year. However I quickly tried moving this to DOY==182 and that didn't fix it.
• the stress calculations are also assuming year end == 365
• the biggy...I'm assuming the pheno can be calculated from the current year when really it should be taking in the last half ot the previous year and ditto the final growth period at year end. Obviously matters, but less than why it currently doesn't work