Known Issues:
*Cannot estimate source correlation when more than 2 isotopes are estimated. This is due to computational issues in jags. For now source correlations are set to 0 when estimating more than 3 isotopes.
*Cannot estimate diet contributions when only 1 isotope is used.

v0.4.1
*fixed error in plotting  concentration dependence.
*updated citations.

v0.4
*fixed concentration dependence calculation with 'n+1 sources'.
*updated error messages when plot is unavailable to be more informative.
*changed concentration precision prior from gamma to exponential distribution (with rate = 0.001). There was trouble inverting the matrix when the gamma distribution was used along with more than 3 sources. 
*added the ability to do parallel chains on machines with multiple processors (needs to have more than 1 chain run to be useful). 
*fixed the way range is determined in the diet source curves.
*removed correlations when more than two isotopes are calculated.
*updated vignette.

v.0.3.1
*fixed mislabeling of diet contribution curves that sometimes occurred
*fixed mixing space x and y axis labels. labels are now read from data file.
*increased the default spacing in mixture error plots so that ellipses will not be outside the axis ranges.
*checked runs under R 2.14.0 and jags 3.1.0

v.0.3
*updated vignette to include an example analysis.
*added group level estimates to the dietary source contributions plots. these are shown as broken lines.
*updated mixing estimate plots to use the density function
*fixed error message on 2 source model when no concentration dependence is present.
*added shades of color to observation plots to identify subsources
*added color option to observation plots, also now allows indefinite number of sources on observation plots
*changed observation plots to only include point observations.
*added function to load previously run data and make plots.
*added appropriate colors to the source contribution plots.


v.0.2.1 
*fixed bug on 2 source plots


v0.2 
4/7/2011
* fixed bug when all text files are included in the model.
* fixed subsource estimation procedure.
* fixed group estimation procedure.
* updated posterior diet contribution plots to include group estimates.
* fixed 2 source mixture and estimation plots.
* cleaned up values of input data passed into run.jags
* cleaned up output variables returned from run.jags
* added vignette