Added some builtins.
Made the parser a little more robust.
Added some syntax for infix operators to the Shell parser.
Corrected a bug in the 'plus' builtin. Don't use value without forcing them !
Changed the naming scheme for the shell scripting language
Prepared MeXa for the introduction of lambda-expressions
Added support for grouping parens in addition to eval parens.
Finished implementing lambda-abstractions in MeXa
Started debugging the MeXa interpreter.
Added simple logging facilities.
Unsatisfying commit
Corrected the last bug of MeXa, the instanciation of nested lambda-expressions.