include xfile in picirn.h
add pic_fdebug
error report is propagated through pic->err
pic_debug family return obj
add some user functions to manipulate ports
add pic_errorf
clarify wrong number of arguments error message
dont consume arena in pic_append
fix #38
clarify some error messages
Merge branch 'master' of git://github.com/wasabiz/picrin into srfi1
fixed trivial bug
[bugfix] compiling big library faults with arena overflow
fixed trivial bugs
Merge branch 'master' of git://github.com/wasabiz/picrin into srfi1