Merge pull request #80 from pmienk/master

Fix #79
Problem: Hard for casual users to add new known projects
Solution: Add zproject_known_projects.xml to model known projects
Side-effect: Gets rid of all project-specific gsl code
Resolves #58
Merge pull request #81 from jemc/master

Problem: Hard for casual users to add new known projects
Added known projects: drops, hydra, and jansson
Merge pull request #82 from jemc/master

Added known projects: drops, hydra, and jansson
Problem: No default descriptions for methods in zproject_class_api
Solution: Use reasonable default descriptions for constructors and destructors
Merge pull request #83 from jemc/master

Problem: No default descriptions for methods in zproject_class_api