class Schruberry
pxd clas chunks + fix compile errors carray
chunk class (todo: signature not compatible)
class chunk
cdef class carray
copy ctable stuff to ctable_ext
move ctable stuff to ctable_ext + test
undo unnecessary "casting"
remove unused definitions
no public declaration needed
fix pxd dtype declaration problem
move numpy & cython imports
move definitions (avoids duplicity)