Handle overflows. (issue #12)

Cookie names and values that were over 1KB could previously
use more workspace memory than assumed. Cut such cookies of
during parsing/assignment.

Conflicts:
	src/vmod_cookie.c
Adopt for Varnish Cache Plus.
Travis configuration for Varnish 4.0.
Travis node package index is out of date.
Forgotten sudo. No sandwich for me.
Require recent autoconf.

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)

Conflicts:
	configure.ac
So much for wildcards.

Conflicts:
	Makefile.am
Add /usr/sbin to path when looking for varnishd.
Pass VMOD_DIR to make distcheck

The VMOD_DIR returned from pkg-config does not take prefix and similar
variables into account. Make sure to pass an explicit VMOD_DIR that
the build process has write access to.

Fixes #8

Conflicts:
	Makefile.am
Require libvarnishapi.

Exit with an error if we can't find libvarnishapi, instead of
just warning about missing macros.

Conflicts:
	configure.ac
Work against a working distcheck.
Use a single line.

Conflicts:
	src/Makefile.am
Update to current standard.
Work around automake naming.
Docfix increased stack usage for filter_except().

Proper solution would be to used the workspace
for the whitelist instead.
Buffer on the heap instead of the stack.

Varnish 4 runs with a reduced per-thread stack, which
the blunt array used for whitelist buffering overflowed
without much grace.
Simplify test case.
Cleaner overflow test.
4KB is what the RFC says.
Big-ish cleanup.

Better handling of overflows.