addex_vec base (broken program)
started replaceing d[] with (*this)[] method in vec class
replaced "length()" with template parameter "L"

Also replaced "d[ ]" with "(this*)[ ]". So it uses a method call instead
of direct access.
more comment info
added inherited constructors to vec<bool, L>
fixed possible no return
moved assignments to vec_base

also added more vec<bool, L> prototype
moved operator== to vec_base
removed op. = and op.== prototypes from vec<bool, L>

These should now be inherited from vec_base
Modify VecTest.cpp
fixed endif by adding comment
added "general implementation comments"
made conditional look less ambiguous
remove bool method
implemented vec<bool, L>::operator! ()