Remove the build_time method, use source_date for clamping all package times

[newpavlov]

The package build time is now gets clamped by date provided to the source_date method.

[dralley]

@drahnr @cmeister2 Please evaluate in the context of #156, do you think it's OK to squash build_time and source_date into one option?

[dralley]

Awaiting consensus on #156 (comment)

[newpavlov]

@dralley
Any updates? IIUC you've agreed in the issue that we need proper bitwise reproducible builds.

[dralley]

@drahnr Can you live with this?

[dralley]

build_and_sign() ought to use the source_date_epoch timestamp during signing

[newpavlov]

build_and_sign() ought to use the source_date_epoch timestamp during signing

It already does, no? Or have I missed something?

[dralley]

I missed that part. In that case can we just replace sde with self.source_date_epoch? It's much clearer.

[dralley]

Also, if we're passing our own object rather than "just" an epoch value, source_date might be better honestly.

[newpavlov]

In that case can we just replace sde with self.source_date_epoch?

if we're passing our own object rather than "just" an epoch value, source_date might be better honestly.

Done.

[dralley]

See one last comment about changelog