Add ICAO registration country flags

[don-willingham]

Display the country's flag next to the ICAO registration two character code.

[hhrhhr]

"Files changed 254"... you have never heard about the CSS image sprites or Base64 sprites?

[don-willingham]

I'm a CSS noob, so I honestly haven't heard of those. Thanks for pointing them out. I grabbed the set of flags as individual icons. The author/maintainer of FlagFox said he even tweaks the colors occasionally. It was straightforward to have the http server handle the flag URLs, if it was a single image file, that could be streamlined. If the flags are embedded in the html file, then I can revert the changes to handle the flag URLs. In one case, I would have to compose an image of all the flags, and reference the location of each, which may not be as straight forward as one might think, because some icons are taller or wider than others. Either way, I would want to maintain the flags as individual icons, and automate the composition of the image with all the flags and the offsets, or the Base64 encoding. I think I would lean towards using the Base64 method.

[don-willingham]

@hhrhhr don-willingham@fdd4055 implements base64 encoded images. The individual flag icons can now be removed.

[hhrhhr]

If you are interested in my opinion, the "database" with the flags looked best in a separate file, which would be generated during "make all".

but to be honest, I am personally against the transformation of the pure decoder in another all-in-one utility. this is not unix-way ;)

[don-willingham]

It would be a bit cleaner to move the flags to another (generated) file. Instead of generating the flags content, and copy/pasting it in. Before dump1090 gets much bigger, it would be nice to have it broken down into components. I'm not planning on refactoring into these components. I like the unix-way, but there are other valid metaphors, such as a plugin architecture, or maybe moving the core of dump1090 into a library that several applications can use.

[don-willingham]

There is now a single flags.js that contains all of the flags base64 encoded. Since all of the base64 encoded values started with a common prefix, the script that generates flags.js figures out that prefix, and factors it out.