Fix empty 'version' file
Fix empty 'version' file

This teaches the makefiles to construct the version string again so
it can be emitted to the 'version' file for packaging.

Fixes failing nightly builds.

rust-lang/cargo,eminence/cargo,eminence/cargo,durka/cargo,tsurai/cargo,durka/cargo,eminence/cargo,durka/cargo,achanda/cargo,rustyhorde/cargo,nipunn1313/cargo,tshepang/cargo,tshepang/cargo,achanda/cargo,rustyhorde/cargo,tsurai/cargo,rustyhorde/cargo,nipunn1313/cargo,rust-lang/cargo,tsurai/cargo,tshepang/cargo,vojtechkral/cargo,rust-lang/cargo,tsurai/cargo,vojtechkral/cargo,rustyhorde/cargo,vojtechkral/cargo,achanda/cargo,rust-lang/cargo,nipunn1313/cargo,tshepang/cargo,vojtechkral/cargo,eminence/cargo,durka/cargo,achanda/cargo,tsurai/cargo,nipunn1313/cargo