Merge pull request #110 from hintjens/master

Problem: grammar had become specific to autoconf
Problem: Class API models cannot generate callback typdefs
Solution: Add <callback_type> support and example code
Merge pull request #111 from jemc/master

Problem: Class API models cannot generate callback typedefs
Problem: Ruby bindings do not support "interdependent" classes
Solution: Add the #__ptr and #__ptr_give_ref methods and use them
to pass pointer values from inside ruby objects
Merge pull request #112 from jemc/master

Problem: Ruby bindings do not support "interdependent" classes
Problem: Ruby bindings do not convert ptrs to object wrappers
Solution: Add some basic infrastructure to do this in the known cases
Merge pull request #113 from jemc/master

Problem: Ruby bindings do not convert ptrs to object wrappers
Problem: Ruby binding callback functions have poor exception handling
Solution: Force the user to implement his/her own exception handling
Problem: Ruby binding coerce_to gets incorrectly downcased
Solution: Add the magic colon to the GSL interpolations
Merge pull request #114 from jemc/master

Problem: Ruby binding callback functions have poor exception handling
Problem: Ruby bindings cannot identify freshly allocated return values
Solution: Recognize the "fresh" property in class API models
Merge pull request #115 from jemc/master

Problem: Ruby bindings cannot identify freshly allocated return values
Problem: String constants in class API model fail when have comments
Solution: Fix incorrect usage of GSL operators
Merge pull request #116 from jemc/master

Problem: String constants in class API model fail when have comments
Problem: AM_CPPFLAGS not included while compiling selftest program with automake (an issue with the .am file generated by zproject)
Solution: corrected the construction of src_$(project.prefix)_selftest_CPPFLAGS
Merge pull request #117 from oikosdev/master

Problem: AM_CPPFLAGS not included while compiling selftest program
Minor editing and documentation cleanups for API model.