Auto merge of #347 - erickt:master, r=erickt

Add "include" to Cargo.toml files

This filters out junk files from the crates.

Closes #331.

serde_codegen/Cargo.toml

@@ -8,6 +8,7 @@ repository = "https://github.com/serde-rs/serde"
 documentation = "https://github.com/serde-rs/serde"
 keywords = ["serde", "serialization"]
 build = "build.rs"
+include = ["Cargo.toml", "build.rs", "src/**/*.rs"]
 
 [features]
 default = ["with-syntex"]