remove first-dupe-to-end in create_pyra_sizes(), ditter around with comment for it
add commmented-out conv_ana_2 test with a slightly denser example net
img_io: add img_copy_to() and upsample_2x() functions
add lr shift opts and get_wh() template gettor to u32_pt_t
fix to blf_pack; add img_pyra_pack mode and create_prya_imgs() function

note: in blf_pack, the fix was to remove a too-strong assert and handle the resultant case