Minor cleanups

[u1f35c]

These are a handful of minor cleanups I made while updating the Debian packaging for retroarch-assets.

• Clean up executable permissions on data files
• Remove duplicated scripts
• Rename a source file to match the generated file base name

[baxysquare]

The majority of the files with permission issues are ones that I contributed. I'm guessing the issue comes from the fact that the source files were created on a Mac. Is there a command or script I should run to fix the permissions before I make contributions?

[u1f35c]

I ended up doing:

• find . -type f -name *.pdf -executable -exec chmod -x {} \;
• find . -type f -name *.png -executable -exec chmod -x {} \;
• find . -type f -name *.svg -executable -exec chmod -x {} \;
• find . -type f -name *.txt -executable -exec chmod -x {} \;

to make sure all those file types weren't executable (and a find . -type f -executable is useful for seeing all the executable files). I'd actually expected the issue to be more likely to have come from the Windows world than a Mac; I've no suggestion for how to avoid it on new files.

[u1f35c]

xmb/convert.sh already exists as scripts/xmb-convert.sh

Rebased on top of current master to fix the merge conflict (some of the files with fixed up permissions have since been removed from the repo)