This has been fixed in v1.9.17 of App Engine:
https://code.google.com/p/googleappengine/issues/detail?id=11346

This reverts commit 9556e1736d.

Fixes #67.

This is to work around a bug where App Engine, which as of this writing
runs Go 1.2, builds code which uses the "go1.3" build tag. See #67.

This bug is being tracked at:
https://code.google.com/p/googleappengine/issues/detail?id=11346

This has the additional benefit of removing the need for a go1.3 branch.