v0.4.3

Merge the recent changes in the devel branch to master.

This new patch version adds additional options for pheromone.calculation:

• Allows for the pheromone levels to update based on standardized observed regression coefficients ("beta")
• Allows for the pheromone levels to update based on both the latent and observed regression coefficients ("regression").

Updates to the plot method for the antcolony class

• New plot showing changes in mean.betas when pheromone.calculation == "beta" or "regression"

Updates to the manual for antcolony.lavaan and plot.antcolony.lavaan

• Includes information on changes to pheromone.calculation
• Notes that the default for pheromone.calculation is "gamma"