[Ecls-list] Latest changes

[Juan Jose Garcia Ripoll]

Latest changes. Notice that the new code for processing command line options
introduces incompatible changes, but allows for compilation of multiple files.

* Design:

 - Simplified the structure of the frame stack, removing redundant fields.

 - Reworked the structure of the lexical environment to accelerate access to
   variables.

 - New hash routine, similar to SBCL's one, faster and leading to fewer
   collisions between similar strings.

* Visible changes:

 - The code for handling command line options has been redesigned. Now multiple
   -compile options are allowed; the -o/-c/-h/-data options have to come before
   the associated -compile; we introduce a new -rc option to force loading
   initialization files; errors during initialization are intercepted and cause
   ECL to abort.

I am working on a closification of the compiler code. Maybe after that I will
find some time to review the callbacks code.

Regards,

Juanjo