Rollup merge of servo#7049 - servo:cargoup, r=metajack

Upgrade cargo to 0.4.0-nightly (425fd85 2015-08-05)

Pick up rust-lang/cargo#1830

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Author: Manishearth

cargo-nightly-build

@@ -1 +1 @@
-2015-06-24
+2015-08-05