use nunicode for proper to_upper/to_lower string conversions
add <cstring> for std::memset
Merge branch 'master' into nunicode

Conflicts:
	configure
	styles
increase buf to hold trailing '\0' + better names
Merge pull request #530 from mapbox/nunicode

use nunicode for language aware to_upper/to_lower string conversions
cleanup after 195560090/#309/#530
fix 'run-linux' target - refs #534/#511
make util::utf8_to_utf32::convert() static
add -s,--style command line option to specify path to the style
e.g ./build/Release/mapbox-gl -s ./styles/styles/bright-v5.json
line-offset -> line-gap-width
More concise
Axe the 16-px line width limit
v6: min-zoom -> minzoom, max-zoom -> maxzoom
Reinstate 16px line width limit
Implement v6 filters
Use v6 styles
Update styles
Render ⇢ layout, style ⇢ paint

https://github.com/mapbox/mapbox-gl-style-spec/issues/166
Update test suite
Single text positioning property

https://github.com/mapbox/mapbox-gl-style-spec/issues/197