optimizeR 1.2

[loelschlaeger]

Goals:

• Functionality to pass gradient / Hessian function to optimizer
• Functionality to pass lower / upper limit to optimizer
• Improve Dictionary (at least optimizers from optimx)
• Write vignette that explains (also new) package functionality
• Implement a $summary() method for an optimizer object that gives an overview of the optimizer, its arguments, and its properties