This @fix the parsing of dirs from the xdg env vars. Now always remove
the leading / char from the paths.
This was causing lots of trouble on my system, where XDG_DATA_DIRS is:
/usr/local/share/enlightenment:/usr/local/share:/usr/local/share/:/usr/share/
At first /usr/local/share was added 2 times in the list, one with the / and one
witout, causing a double lookup for each file.
Secondly the icon cache was totally unusable as the cached paths ended up
as: /usr/share//icons/Mint-X/places/32/folder.svg. The double / in there
was making the cache lookup to fail and anways return the biggest icon
available. Causing a big system slowdown whe searching for icons.
As a bonus the function now use eina_str_split instead of the custom splitting
code that require a bad special handling for the last item.