Allometry bugs:
 - allom.BayesFit was missing prior on mean
 - read.allom.data: added USFS spcd to variables returned. Added this to the variables read by allom.BayesFit
 - AllomAve: added input ‘allom’ to outputs saved to RData
Allom: debugging
 - Dropped ‘name’ from PFT definition for non-database runs
 - Added an example of a multi-species PFT
Merge pull request #91 from mdietze/master

Allom: debugging priors, multi-species support, and setting up variables to start "random species" effect version