Added enum for GSL optimizer solver types.

Also added setter and defaulted to BFGS2.
Added setter
Helper function

To determine if GSL optimizer needs a gradient
.gitignore
Factoring out minimize code to separate function

In preparation for adding gradient free part.
Rename GSL optimizer enums

Closer to GSL documentation
Turned on multiple solvers for gradient algorithms

Also renamed a few internal variables for better readability
Only print error message on 1 processor
Adding gradient free version of GSL optimizer
Now enable all solvers
Resolved a couple of goofs from rebase.
Use options in gradient free algorithm
Add capability for user to set step size

This is for gradient-free GSL optimizer algorithms
Fixed rebasing gaff
GslOptimizer test now also runs Nelder-Mead
Removing atavistic todo's
Make fdf parameters settable by the user
A little leaner code
Merge pull request #270 from pbauman/gsl_optimizer_solver_types

Gsl optimizer solver types