Add debian packaging files

This doesn't quite work, since the debuild stuff refuses to see the
rustup-installed cargo/rustc, which is required for our build.

debian/control

@@ -0,0 +1,27 @@
+Source: bscreensaver
+Maintainer: Brian Tarricone <brian@tarricone.org>
+Section: x11
+Priority: optional
+Standards-Version: 3.9.2
+Build-Depends:
+  debhelper (>= 13),
+  pkg-config,
+  libxcb-randr0-dev,
+  libxcb-xfixes0-dev,
+  libxcb1-dev,
+  libgtk-3-dev,
+  libpam0g-dev,
+  cargo,
+  rustc,
+  help2man
+
+Package: bscreensaver
+Architecture: any
+Depends: ${shlibs:Depends}, ${misc:Depends}
+Description: secure X11 screen locker
+ BScreensaver is a privilege-separated screen locker that attempts to
+ be as secure as possible, meaning that a crash one one of its
+ non-critical components will not cause the screen to unlock.
+ .
+ It is fairly barebones so far, and only supports blanking the screen.
+ There is a single unlock dialog implementation that uses GTK3.