add number prefix to contrib libraries
add for macro library
rewrite an unavailable symbol into an available one
added null operator to (picrin control list)
add (picrin control list) doc
Merge pull request #155 from stibear/srfi43

revise (srfi 43)
fix #153
update docs. mentioning new srfi libraries
vectors, blobs, strings with equal contets are equal
check length before compare contents
style fix
fix type warning (int and size_t)
Merge branch 'equality'
[bugfix] support vector literal in quasiquote
[bugfix] wrong size for read string
unlock reader test
allow "(a . b #;c )"
unlock some of environment-variable tests
unlock more reader tests
delete trailing whitespaces