support for Hygienic macro

[francescoagati]

a support fonr Hygienic macro can avoid error in definition of variable for local scope

http://en.wikipedia.org/wiki/Hygienic_macro

[jeromebaum]

Personally I'd say let's handle this later. There is other stuff that needs work.

Rather than adding in hygenic macros, let's bring pharen to the point that hygenic macros can be implemented in pharen (similar to this).

[Scriptor]

I agree, although a gensym function could probably be done after a bit of work, more effort needs to be put into making general use of Pharen easier.