Move source images (.psd, .svg) from images to img-src directory
Add script to generate picard.qrc from png images in images directory
Make compile.py runnable from anywhere and importable.
Mark compile.py and makeqrc.py as executables, they have python bang path.
Use resources makeqrc and compile code, reducing code redundancy.

An empty __init__.py file was added so functions can be imported.
Use len() instead of a counter.
Use unix eol in generated ressource file.
Merge pull request #136 from zas/resources_tools

Improve resources tools