Provide end to end compilation helper

Add "compile" option to PushPop.main, will emit an assembly file
which can then be compiled to in memory instructions and executed
by the pushpop vm.  The process is slightly brittle, there are errors
that won't be caught until the asm is built, but it works.

Provides a sample file demonstrating syntax, and compilation.

Also, address some minor bugs to make this all work, namely strings
were doubly quoted in assembly output. Added notes for other
non-major bugs.