implements (srfi 60)
initial read implementation
store rlabels in global state
api changes of reader/parser
remove flex dependency
add pic_open_input_string
add pic_eof_p
[experimental] update xfile
allocate buffer in +1 size
update xfile
use xprintf instead of printf
comment readers should return undef values to report continuablility to
the parent function
improve error messages of load function
support nested block comment
fix EOF handling
allow symbols with leading '.'
fix read_vector bug
update xfile
hold integers in 64bit size
Merge branch 'abandon-flex'