check and fix big-endian

[rurban]

RS,RL,handles still broken on mips32 and ppc64 big-endian.

I'm adding now qemu binfmt support (debian-style) to the scripts (env LD_LIBRARY_PATH='/usr/powerpc64-linux-gnu/lib), just debugging is tricky there.

• [X] compile on mip32 and ppc64
• [X] decode and convert to JSON
• [x] bits_test
• [x] bit_read_DD codes 2 and 1
• [x] decode_r2007
• [x] add_APPID
• [ ] check-minimal: encode, codepage conversion, dynapi
• [ ] check full

[rurban]

Fixed most issues, it can be successfully read and converted to json.

Problems exist in encode, and esp. the dynapi (the memcpy) on encode in add_LibreDWG_APPID(), getting the APPID_CONTROL num_entries. But the dynapi unit-tests run ok.