Add notes for Chapter 4

- also in source files

Signed-off-by: Zlatozar Zhelyazkov <zlatozar@gmail.com>
Initial commit for Chapter 5

Signed-off-by: Zlatozar Zhelyazkov <zlatozar@gmail.com>
Add more notes especially for 'permutations' function

Signed-off-by: Zlatozar Zhelyazkov <zlatozar@gmail.com>
Clean up auxfns.lisp

Signed-off-by: Zlatozar Zhelyazkov <zlatozar@gmail.com>
Add macros examine function

Signed-off-by: Zlatozar Zhelyazkov <zlatozar@gmail.com>
Add package notes

Signed-off-by: Zlatozar Zhelyazkov <zlatozar@gmail.com>
Add nconc notes

Signed-off-by: Zlatozar Zhelyazkov <zlatozar@gmail.com>