[QGIS-Developer] SVG icons in QGIS

[Jonathan Moules]

Hi List,

The more I look at the current SVG icons, the more I'm thinking it 
really needs some TLC (Tender Loving Care). As far as I can tell, icons 
are categorised by the directory they're in, so if you want an icon to 
appear in two categories, you put the icon in there twice... and so 
that's just what has happened! I suspect the current set has simply 
accreted over time.

Examples of weirdnesses:
* The "food" and "entertainment" categories are basically identical, but 
have different icons for the same thing.
* There are at least 7 near-identical aeroplane icons(!)
* There's cycle parking and cycle locking, but no cycle? No car (that's 
under "gpsicons") but two taxis? Oh, and 5 (five!) aeroplanes to choose 
from, and multiple types of train. And that's just "transport".
* "Shopping" has a hammer and a pawprint in it... well, I mean, you can 
buy those things sure, but that seems like a rather odd place to put them.
* "landmark" seems to basically be a subset of "religion", with a museum 
and a weird icon for a "school" thrown in for good measure.

I'm sure there are many more.

Given the importance of a good symbol library for cartography, this 
seems like a fairly significant issue, but fortunately it's pretty 
"easy" to fix (compared to writing a data processing algorithm anyway ;-) ).

My thoughts:
* Move the svg's into a single directory. (Though would break any 
current projects symbology using them I guess?)
* Use a metadata file to categorise them, so you get a list of 
categories as now and a single symbol can be in multiple categories.
* Add a search feature so the user can quickly find "museum" without 
having to guess where it has been categorised.
* Clean up the current symbols by removing duplicates.
* Add the font-awesome symbols (per my thread on the User List) to fill 
in the gaps and flesh out the collection. As a bonus, it comes with 
metadata for categories and search terms (YAML files).

* bonus - metadata is internationalised so "museo" (IT), "muzeu" (RO), 
etc would also work for finding that museum.

Thoughts?

Cheers,
Jonathan