Problem: fragile to reinstall when project changes

The lack of generated makefiles in the project means that when we
add a new file, for instance, we have to re-run the entire build
process before installing. This continually trips me up since its
different from our normal workflow.

Solution: make zproject workflow look like the rest

(./autogen.sh && ./configure && ./make install)
Updated project makefiles
Merge pull request #95 from hintjens/master

Problem: fragile to reinstall when project changes
Problem: need linking to curve crypto library

Solution: add libsodium to list of defined projects
Merge pull request #96 from hintjens/master

Problem: need linking to curve crypto library
Problem: Class API models do not support constants
Solution: Add constants to models and generated @interface headers