Disable exec symlink resolution for PostgreSQL 9.2

When building PostgreSQL with plugins under NixOS, NixOS will create a
postgresql-and-plugins directory which symlinks PostgreSQL and all the plugins
into a single directory. Unfortunately, the plugins will not actually be usable
by PostgreSQL because it will still try and locate them in the original
PostgreSQL share directory, not postgresql-and-plugins.

In this commit, I have patched resolve_symlinks to always return success, which
matches the behavior if HAVE_READLINK is false (so presumably invalid paths are
never passed to this function).
nixos/nginx: allow to specify which package to use

This enables to override which plugins to include with nginx by allowing to change
nginx package. I also removed webdav option in nginx nixos module, because you
can now specify this by overriding nginx package.
Attempt at compiling MilkyTracker, but recent zlib version may have broken it.

There's a zlib version included with milkytracker,
but there's no makefiles for it. I've only included
the header here, but it fails at link-time with
several 'undefined reference' errors, which simply
means it can't find the definitions, e.g. compiled
zlib.
There's bug reports on other package systems although
unfortunately still unresolved.
https://bugs.archlinux.org/task/31324
http://lists.freebsd.org/pipermail/freebsd-ports/2013-March/082180.html
MilkyTracker: fix build, use system zlib and decompressor patch

Also add JACK support
MilkyTracker: Tidy up, sort buildInputs and use the attrPath for the license
fetchsvn: handle redirect(s)

Instead of failing if the server redirects us to a new URL, accept up to
2 redirects by printing 2 extra p's to subversion.
Make touchpad button mapping configurable
Add qvim - an experimental Qt gui for Vim

vim-qt has the most complete set of Ctrl-Alt-Meta binding functionality.
For example, qvim is able to correctly bind keys like Alt-<nonlatin>.
More: https://bitbucket.org/equalsraf/vim-qt/wiki/Features
qvim: clean up the code
Merge pull request #1 from cillianderoiste/add_milkytracker

Add milkytracker
Added milkytracker: Compiles and runs.
Merge pull request #1170 from grwlf/qvim

Add qvim - an experimental Qt gui for Vim
Merge pull request #1164 from kirelagin/master

Make touchpad button mapping configurable
Merge pull request #1159 from bjornfor/fetchsvn

fetchsvn: handle redirect(s)
Merge pull request #686 from ocharles/postgres92

Disable exec symlink resolution for PostgreSQL 9.2
Merge pull request #1181 from Zoomulator/master

New application: Milkytracker v0.90.85
Merge pull request #1099 from offlinehacker/nixos/nginx/package_change_support

nixos/nginx: allow to specify which package to use
grsecurity: Update to 2.9.1-3.2.52-201311021628
paxctl: New package

A tool for controlling PaX flags on a per binary basis.
gradm: New package

grsecurity's RBAC administration utility.