gummiboot: fix INSTALL script; misc twerks.
gummiboot: fix tyop in the post-install kernel hook.
xbps-git: bump (misc constification).
linux-tools: update to 3.16.
tmux: install example config files and vim syntax file

License is BSD, not MIT.
Introduce a way to override dependencies for all pkgs thru a file.

The `etc/defaults.virtual` file contains the default replacement
for our use cases; at this moment we only use it to use `eudev`
rather than `systemd` for udev.

If `etc/virtual` exists it overrides the settings of `etc/defaults.virtual`.
srcpkgs: switch pkgs to depend on libudev again; we use virtual replacements now.
New package: pwnat-0.3
fatrace: update to 0.7.
xdaliclock: update to 2.41.
mdadm: update to 3.3.2.
pv: update to 1.5.7.
radvd: update to 2.6.
xdaliclock: nocross=yes
perl-IO-Socket-SSL: update to 1.997.
perl-IO-Socket-Socks: update to 0.65.
perl-LWP-Protocol-https: update to 6.06.
perl-LWP-Protocol-socks: update to 1.7.
perl-Net-SSLeay: update to 1.66.
sbcl: update to 1.2.3.