Cdef work (#361)

* cdef: WIP

* cdef: now calling cdef_find_dir_c (but only on the first block)

* cdef: call cdef_find_dir on every block (only safe for size % 64 == 0)

* cdef: apply CDEF to luma with pri_strength 7 and sec_strength 0.

* cdef: only apply to full 64X64 filter blocks for now

* cdef: signal cdef strength

* cdef: comment out printing

* cdef: first attempt at applying CDEF to chroma planes

* Corrections to first CDEF attempts

This is still not quite first cuts, but it is basically functional.
It still hard-codes specific CDEF strengths.
There is still an occasional block mismatch.

* Implement CDEF paramters, remove hardwired settings

Add CDEF settings to the FrameInvariants, rather than using hardwires
strength values duplicated in multiple locations.

* Remove last CDEF dependency on libaom

* Remove unrelated change from CDEF work

remove -r rec_file.y4m from rav1e command line