make encoding setup code safer by not expecting sys.getdefaultencoding() to safely return a bytes object

--HG--
extra : transplant_source : cZx%3E%03l%AC%EDK%E3%C2%F2%2C%9BV%E5%EC%5D%B7%C8

--HG--
extra : transplant_source : M%D5%2C%C2%15%9E%3C%BC%3C%89%25n%95%DF%5C%B8%B5%C5%B8%D9

--HG--
extra : transplant_source : %F3%9A%B7r%F7%DB%C7%88%2B%D2%A4%9C%5E%0FT%B8_XS%D2

fix ASCII compatibility check in __Pyx_init_sys_getdefaultencoding_params(): strncmp() stops at first NUL byte which is the first byte in this case (i.e. no comparison is done at all)

--HG--
extra : transplant_source : A%2B%5BO%82%05%F7%DEm/%8Ao%08%121%96%8Ao%AB%8C

--HG--
extra : transplant_source : %CD%DB%8CT%85r%FF%0B%1C%60%B3%CD%F8%16%D8%E3%EC%C7%0BL

--HG--
extra : rebase_source : 4cc5a2b5b9044e06fca82d216aa5a3c919abf033

utility code construction for struct conversion requires constructing the field conversion functions as well

--HG--
extra : transplant_source : %A3%81%87%E2%0A%20%DA%7D%7E%5B%A0%9B%80i%F9%8Az%9B%F3%DC

simplify test for GCC >= 2.95 for branch prediction

document memoryview attributes better

--HG--
extra : amend_source : 9ae2e52935ae16af23c35b6329d53e559b7c39d0

Fixed typo

(I know, I know. It was just too visible.)

apply freelist type check also when *adding* dead objects to the freelist to make sure their eventual cleanup works correctly

--HG--
extra : amend_source : 6c9be6e15396919e08090d9d12557c4255fd8a3c

revert to using malloc/free for data buffer allocation in case external code wants to fiddle with it

make it easier for the C compiler to prune some useless error checking code in cython.array constructor

--HG--
extra : amend_source : 4d5d9dc96421710652afe8614c9f32db26cc88c1