major autoconf cleanup plus initial support for android

First off,

DON'T PANIC!

This pull request is like a code dump but in reverse... yet, it's all for a good cause :-)

I've removed most of the files under the autoconf directory, and moved most remaining files around, so that you can now run `autoreconf -Iautoconf/m4`  (note that it's `autoreconf` and not `autoconf`) in the project root directory and regenerate the `configure` script and `config.h.in` - and there's no need to copy files around after that.

With this, burp can now be cross-compiled for ARM based android devices, and it seems to run fine as a client (tested cert generation, backup, list, restore) when launched manually in a shell with root privileges, on an emulator.

Next, I'm planning to wrap burp with an app that will provide a gui for configuration and manual launch, access to contacts, text messages etc, and scheduling. I've never written an android app before, but it seems that everybody nowadys is doing this, so it can't be that hard ;-)

Please review and pull,
Thanks,
Avi