[GSoC 2016] Progress on External runtime functions

After the codebase merge a lot of new tasks and issues turned up. One of the important tasks is adding runtime support for externally defined functions in Prelude. I have made a complete list of unimplemented External functions and their priorities. Current status of this module can be found here.

Before this task I also worked on making a more robust test suite in ruby. All tests can be run using the rake test command and in order to force recompile all intermediate files from scratch for testing, the command rake ftest can be used.

I am currently working of refactoring expressions.rb to facilitate the definition of some External functions.

The complete list of upcoming tasks can be found here.