Build number is not immediately used after being generated

[ZevEisenberg]

On build, the build number is generated by a script. However, the previous contents of BuildNumber.xcconfig are used for that build, and the new values are not used until the next build. This is mitigated (but not fixed) by 1fa8149.

You can see this by doing the following:

1. Open BuildNumber.xcconfig.
2. Set both build numbers to something random like foobar.
3. Do a build.

The resulting build will have foobar as the build number, even though the xcconfig file will be updated with the new number. The next build will use the new number.

As a workaround, you must do a build before your final release build if you are releasing the app. And yes, Zev, you're talking to yourself in the second person.