Using xcode-select to select an Xcode directory that is named with a space in it causes build failures

[adam-mapbox]

@1ec5

sudo xcode-select -s /Applications/Xcode\ 6.4.app/

make ipackage

* Loading install script 'https://github.com/mapbox/mason/blob/boost-system/script.sh'...
/Users/adamhunter/Documents/MapBox/mapbox-gl-native/mason_packages/.scripts/boost-system.sh: line 32: /Applications/Xcode: No such file or directory
/Users/adamhunter/Documents/MapBox/mapbox-gl-native/mason_packages/.scripts/boost-system.sh: line 34: ./version: No such file or directory

[1ec5]

Relevant lines:

https://github.com/mapbox/mason/blob/b30e09ebc724b17cd000721938b3d26d3264900d/mason.sh#L71 (master branch) https://github.com/mapbox/mason/blob/b30e09ebc724b17cd000721938b3d26d3264900d/mason.sh#L419 (master branch) https://github.com/mapbox/mason/blob/4027bd620e9de2875650e224227d54f0bef83bb5/script.sh#L32 (boost-system branch)

/cc @springmeyer