[Roadster] preview release

[Ian McIntosh]

I'm now working towards a "Preview Release."  The goal is to create
buzz, attract contributors, and get feedback.  No new features are going
on the TODO list and everything is getting polished.

The preview will be easily installable on at least Red Hat and
Debian/Ubuntu.  It will include sample map and POI data (just one or two
areas-- might as well be somewhere with lots of FOSS hackers) and will
not support importing more data (although it may allow users to add POI
by hand).

Left on the TODO for the PR release:

1) A Points of Interest (POI) system.  I'm just going to wing it until
Steven and Dan have time to work up a spec.  I'll likely create
something sort of like MS S&T and keep in mind that it will have a
community aspect to it later.

2) Possibly finishing GPS functionality.  I'm still not sure about
whether it belongs in the PR.  After all, if we only include map data
for one area, the GPS functionality will only be useful to a small
subset of users.

3) Choosing what map data to include!

Comments are welcome!

-Ian

===
Recently done items:

x Fix Memory spike on zoomlevel 10
x Smooth sliding on double click
x Change welcome window to explain preview release
x Limit zoomlevel to 6-9
x Expand claimed box around text slightly
x Slide, don't jump, to search results if close enough
x Use GTK for about box instead of GNOME
x Make edge scroll corner boxes bigger and L shaped
x Change bounding box tests to use lat/lon instead of int
	x Polygon labeling (Cairo)
	x Line labeling (Cairo)
	x Track drawing
	x Polygon drawing (GDK, Cairo)
	x Line drawing (GDK, Cairo)
x Add a Find "no results" message
	x make it not double-clickable
x Improve single-click scroll to use half of height/width
x Clean up mainwindow:
	x Disable Forward and Back menu items when they would do nothing
	x Disable Zoom In/Out buttons / menu items when they would do nothing