Remove proxy from test cases
Added .swp to git ignore list
Small WIP on Questionaire demo
Fixed ../demos path in Piping
Added debugging wrapper for state machine
Bug fixes for debugger
Added debugable recursive descent parser
Added color to debugger
Fixed debugger color bugs
Restored load_with_models to Load::load
Fixed interpreter stack so that undefined values are not conflated with nils
Tidied up debugger and debugger examples
Updated piping controller for new interpreter framework
Fixed devious bug with printing MObjects

Previously MObjects did not have .inspect defined and uses to_s
instead. However, calling to_s on Arrays sometimes invokes .inspect
on its contents, which causes a loop for MObject. So an alias is
added to make .inspect and .to_s equal in MObject.
Tidied up interpreter kernel
Tidy up piping controller
Updated piping simulator to work with new interpreter framework
Added test cases for Piping
Added system.rb to Piping

System.rb runs the overall simulator and should be used as the primary demo
executable.
Added evaluation capability to lambda calculus language

Lambda formerly was just a proof-of-concept for the debuggable (recursive
descent) parser. Now it is a full-fledged language with evaluation semantics
and, in the future, a debuggable visualization.