Be a total CPP-show-off-douche and make it very easy to add further
variables in the future, provided you can find the magic table.

Presently define three variables:


	REAL storage.$stevedore.free_space
	REAL storage.$stevedore.used_space
	BOOL storage.$stevedore.happy

Still debating if I should add a "SPACE" type to VCL, so that you
can write:
	if (storage.foobar.free_space < 1 GB) {...}

until I decide, it is a REAL, which is less than useful, because
we have no relational operators besides identity for REAL.



git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@5654 d4fa192b-c00b-0410-8231-f00ffab90ce4