Enhance resource location detection.

[mattsgarrison]

app.resources_dirs defaults to /resources but this can be configured per project. Motion-rubberstamp should search for icons in all paths declared by resource_dirs.

[mattsgarrison]

resource_dirs should be an array of strings (paths), so everywhere '/resources' is explicitly called, it will need to iterate over resource_dirs and concatenate that path with the icon filename instead.

If icons are found in non-default locations, they would currently install in the same directory. Perhaps creating a new folder ./rubberstamp or maybe ./original_icons to contains the originals in whichever directory any icons are found in would be a better solution than polluting the current directory with the "working set" of modified icons and their '*_base.png' counterparts.

[GantMan]

I strongly agree with keeping Rubberstamp files inside of a rubberstamp folder. I feel it helps identify where new images came from, for an existing project. It will make sense to most.

Added as issue #15

[mattsgarrison]

Currently motion-rubberstamp gets very angry if a ./resources folder is not present at all. Enhancements to resource detection should consider what happens if nothing is found.