AVIATIONTOOLBOX: alpha version of route mapping tool

I took a little bit of a break after creating the tools to generate
normalized "chunks" from sectional images.
http://aviationtoolbox.org/munge/mosaic

Over the holidays I got back into it and tackled doing something
useful with those chunks. I already revealed my map_image tool which
generates an image given the upper left and lower right coordinates.
https://aviationtoolbox.org/Members/....1&lr_lat=39.6

Now I've created a very simple tool to call map_image for frames
along a route. It's called route_map and it takes the departure
(from) and destination (to) points.
https://aviationtoolbox.org/members/..._lat=39.717329

I wanted to depict the path between the two points but I hate it when
a drawn line obscures something important on the sectional. I decided
that the line is a lot less important than the sectional image, so as
a first shot I made a 2 nm wide highlighted line between the points. I
lose it in some terrain, but I have some ideas for solving that.

Right now route_map generates 1024x768 images. This is just for
testing and will eventually become much more flexible. I have a
version that generates marginless US letter-size PDF but the output is
*huge*. I'm going to work on that some more.

This tool isn't ready for much use and it's likely that I'll break it
while I'm working on it but I just got a letter from someone who is
anxious to see it so I thought I'd share.

Oh, and because I don't have the airport data in Zope yet, for testing
it I added links to my nearby airport locator.
http://lairds.org/Kyler/flying/flights/nearby_airports
If you give an "other airport" you'll get links labeled "sectional
route" for each of the airports in the list.

Enjoy.

--kyler