better error handling, fixes for parallel make, remove generated files from dist

On getting dependencies right:

See automake doc 9.4.1 Built Sources Example / Recording Dependencies manually

Conflicts:
	configure.ac

define PKG_CHECK_VAR if it doesn't exist

Fixes #19

Master: Fixes for #6 and #13

4.0: Fixes for #6  and #13

Access pkg-config variables the autoconf-way

Fixes #13 (github issue)

Fixes #6	(github issue)

Access pkg-config variables the autoconf-way

Fixes #13 (github issue)

Fixes #6 (github issue)

To make it more clear that we provide this as an example for anyone
to use for whatever purpose, change the license to public domain.

Fixes:		#12 (github issue)

Conflicts:
	configure.ac

To make it more clear that we provide this as an example for anyone
to use for whatever purpose, change the license to public domain.

Fixes:		#12 (github issue)

There is a compatibility macro added to varnish.m4 in 4.0.3,
so we can build VMODs on EL6 now.

Inspired by pull request to libvmod-ipcast from Martin Probst.

Let the Makefile install these files on all systems, instead
of having explicit handling of them in the redhat spec and
debian configurations.

This reverts commit cacb7b2a.

Build servers install these in the necessary chroots, format it
similarily to avoid exceptions everywhere.

Conflicts:
	README.rst
	debian/control
	rename-vmod-script
	vmod-example.spec

On EL6 systems the packaged 2.63 version is missing AS_VAR_COPY.
This seems to have been added in 2.63b, released sometime in 2008.

With this commit we cut off any vmod development being done on
EL6 and earlier. (building and running should work)

We need pkg-config and a new libvarnishapi to build, and varnishd to run
the test suite.