sketch out class UTF8::uni_iter, add tools/make-UTF8.sh
UTF8::uni_iter made leaner.
Bug fix: pcbnew hangs up on polygon movement
Plot functions: some enhancements in mirror mode (Pcbnew specific): boards are mirrored horizontally, and the page layout is no more mirrored, and therefore is always readable.
Move "code costly" functions in experimental class UTF8 to be not "inlined", prefering compactness.