Create zrt and zrt-dev Ubuntu/Debian packages

[larsbutler]

We need to create Ubuntu/Debian packages for ZRT. Between (toolchain)[https://github.com/zerovm/toolchain], and ZRT projects, there is a slight circular dependency.

ZRT headers are needed to build the toolchain, and the toolchain is need to build libzrt.

Thus, ideally we would create a zrt-dev package containing zrt.h, etc., which can be used to bootstrap the toolchain. Once that is done, we can create the zrt (libzrt) package.

[pkit]

It should look more like linux-headers than libfoo-dev
Because zrt.o is needed verbatim, AFAIR, and Debian lint will be very unhappy about that.