Typo in BAN configuration

Submitted by:	Clement Gautier via github
Pass struct vfp_entry * to the vfps.
Split the init and fini functions out for VFP's.
Flip the order of arguments to make more sense.
Correct AC_CHECK_PROGS usage
Fix backends and vhosts example

Submitted by:       nublaii via github
Report VFPs in panics
Now that HTTP/2 seems to have confirmed they will not make Content-Length
part of the transport protocol (don't even get me started!) we need to
lift it out of HTTP/1 space and into the RFC processing.
Make it possible to push VFPs both on top and bottom of the stack
and put the V1F VFPs after all the gzip/esi etc. have been pushed.
Sort the list of build requirements.
Update list of documented build requirements.

The list of documented build requirement have not been updated
for a while, and was outdated.

Update the lists with recent data.

Added (commented-out) commands that extracts and formats
this information directly from the packaging files.

Reported by:	frakt
Make this less magical and more readable.
Introduce VFP_NULL as a possible return from vfp->init() to mean "ignore me".
Filter the list and add forgotten python-sphinx.

We only need debhelper when building the debian packages,
and the systemd-units is within a conditional that awk ignores.

Updated the commands to not include these in the future, and also
the Redhat spec file so it should work on a fresh installation.

Noticed by:	fgs
Readline does not belong on this list.

This reflects the debian build files, editline will suffice.
Enable OS X builds on Travis CI.

Travis-CI recently began supporting multi-OS builds:

    http://blog.travis-ci.com/2014-05-13-multi-os-feature-available/

Since we don't have a OS X 64bit build slave currently, let's see if
Travis can help out for now.