Support ARM processors such as the Raspberry Pi

[joeferner]

I have it working on my Raspberry Pi (using my fork here: https://github.com/joeferner/juds) but it requires removing the x86 and x64 targets since Raspberry Pi doesn't support cross compiling.

[mcfunley]

Happy to take a PR for this that doesn't remove x86/x64. Presumably that'd require some more autoconf/makefile jiujitsu.

[joeferner]

I tried a couple different things but I wasn't able to get a build from my machine working on the pi. I might post something on the pi forum about cross compiling.