enable switching between OS X & iOS fat binaries for dependencies
Merge remote-tracking branch 'origin/mapbox-gl-native' into ios-64-bit
re-run configure post-symlink
fix libuv 0.10 support

Add libuv.pc pkg-config file with correct libs and copy libuv.a to
correct location after build.
Merge branch 'libuv-pkgconfig' of github.com:mapnik/mapnik-packaging into libuv-pkgconfig