Add "-ce" to .indent.pro

Looks like I was missing a else cuddling in my indent profile.  This
is now fixed.
Block indent on some code

I have no idea why indent has suddenly gone nuts, but I've found a
workaround.
Use $ORIGIN-relative RPATH in C

This lets me run my C files from anywhere in the filesystem without
installing them.  I was originally trying to avoid this so people
wouldn't use it (ie, so they'd install instead, as that's a lot less
fragile), but having this support makes testing a lot easier.
Add a simple pconfigure test

I'm not entirely sure this is the correct way to go about testing
pconfigure, but I guess it's OK for now.  Essentially this just
invokes the compiler to build things exactly as pconfigure would in
the real world.

I'm still thinking that some sort of approach using mock binaries (ie,
GCC and friends) could get us better coverage: in other words, it's
going to be very tricky to shake out edge cases this way.

The advantage is that it'll actually run the compiler, so we can test
things like options on different systems (which have been a problem).