Properly compress PNGs

Saved 631Kb out of 1,9Mb. 28,1% per file on avg (up to 99,5%).
Removed European Union from countries (-not- a country)
JPEG compression.

Lossless: stripped metadata and other junk from JPEGs for smaller file size.
UTF-8 Charset

See:
https://developers.google.com/speed/docs/best-practices/rendering?hl=fr#SpecifyCharsetEarly
http://stackoverflow.com/a/2526487/3671935
Merge pull request #4 from PierreLvx/master

Image compression ; countries ; charset.