Do not chmod +s chvt: instead, rely on sudo

The SUID flag may be lost on update, and relying on sudo is
slightly more secure.

We create a file in /etc/sudoers.d/ : these files are sourced by
default since sudo 1.7.2p1-1 (Ubuntu 10.04 lucid, Debian squeeze).

Fixes #723.
*/releases: Specify if a release should be tested or not

Each release line is now in the following format:
`release[*][|other,key,words]`

 - * indicates that the release is unsupported
 - keywords are comma-separated, and can currently be `test` or
   `notest`. Default is for supported releases to be tested (can
   be overridden with `notest`), and unsupported ones not to be
   tested (can be overridden with `test`).
installer: Fix accidental prefix match.
enter-chroot: Remap devbroker-access group.

Enables security key users to add themselves to the group, and/or
add custom udev rules.
Merge pull request #1177 from drinkcat/remap-devbroker-access

enter-chroot: Remap devbroker-access group.
Merge pull request #1140 from drinkcat/releases-flags

*/releases: Specify if a release should be tested or not
Merge pull request #727 from drinkcat/sudo-chvt

Do not chmod +s chvt: instead, rely on sudo
Add vtlock command for tests to ensure graphics exclusivity
Don't explicitly include core.
Don't override the log fd
Add xephyr and xorg tests.
Tweak test timing; unmount-chroot is still an issue.
Fix xorg/xephyr test command
test/35-xorg: Dump OpenGL+dri information
35/36-xorg/xephyr: Update to new split test
test/run.sh: Change vtlock function

So we can run multiple commands within the lock.
test/run.sh: Kill subprocesses when test exits

Move trap call so that it is actually executed, and kill any
leftover subprocesses so the test can complete.

Also, unmount chroot with -f.
tests/w?-*: Test all de/wm
lxde: Do not install wicd

sid pulls it in as recommended dependency.