vectors, blobs, strings with equal contets are equal
check length before compare contents
implement circular refarence checking
Merge branch 'master' into equal
Merge branch 'master' of https://github.com/wasabiz/picrin
Merge branch 'master' of https://github.com/wasabiz/picrin
change pic_throw API
throw READ_ERROR when parser raised
support #true and #false literals
Merge branch 'boolean-alternative-notation'
fix bug of `{bytevector, vector}-copy!` with the same src and dst
Merge pull request #162 from KeenS/hotfix

fix bug of `{bytevector, vector}-copy!` with the same src and dst
read rational '123/456' literal
'make tak' broken
add pic_dict_new
add attribute information to closure objects
add attribute function
Merge branch 'closure-attribute'. close #124
remove get_var_from_proc (essentially the same as pic_unwrap_var)
remove var accessor and mutators