Resync 'make makepatch'
Use external protobuf to avoid a build error on unkown functions.
Because we use external dependencies, we cannot use the official build which does not allow those.
Use external icu to resolve link failures.
These all need -I${LOCALBASE}/include now too.
Try to use system libpng, does not work yet (-lpng missing?):

/usr/bin/ld: .: invalid DSO for symbol `png_set_strip_16' definition
//usr/local/lib/libpng15.so.15: could not read symbols: Bad value