Auto merge of servo#229 - Eijebong:synup, r=SimonSapin

Update syn and bump version

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Fix features in syn dependency

Fix features in syn dependency

Auto merge of servo#225 - servo:emilio-patch-1, r=SimonSapin

Bump procedural-masquerade to pick servo#224

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Auto merge of servo#219 - Eijebong:no_more_so_plz, r=SimonSapin

Allow up to 8MB stack size for build.rs to avoid a stack overflow

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