Print an error when unable to open BASH file
Handle GENDIR in BASH

This lets me generate BASH files that can be included in the build
process.  Note that pbashc doesn't actually support this yet, that's
coming!
Add "pinclude_lines()"

The goal here is to allow me to use libpinclude to actually preprocess
a file.  This will (eventually) allow me to eliminate the custom
parser in pbashc.
Silently terminate on empty pinclude call

This is just here to make a test pass that I forgot about.
Actually make pinclude_lines() call the lines function

I guess I just hadn't bothered to do this before...  Whoops!
Make p{bash,perl}c use pinclude

This is a big win: it supports -Iinclude/dir/ as well as allowing me
to remove a whole bunch of nasty duplicate code.
Add a "trap rm -rf ..." to ptest

There should no longer be "/tmp/ptest-wrapper*" directories lying
around the system.
Add LLVM support

This patch allows me to compile LLVM files and link them with C files.
This helps when I want to hand-write some LLVM assembly, for example
to use the multi-word support.