"cargo metadata" should contain license info

[jsgf]

The cargo metadata should include info from the license and license_file fields in Cargo.toml. This is useful for integration into other build systems which keep track of license details.

Ideally license_file should be a full relative path to the file, but maybe its sufficient if its relative to manifest_path.

[alexcrichton]

Indeed! Should be an easy bug to tackle I think, just a few modifications to this block.

[srinivasreddy]

Pls close this @alexcrichton

[alexcrichton]

Indeed!