Add deadlines to several methods

[canndrew]

This change adds a deadline: time::SteadyTime argument to all blocking methods.

I think there's room for debate about whether this is the right thing to do. But it's certainly useful.

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This change is

[canndrew]

It's probably not worth merging this one for now as rust-1.8 comes out tomorrow and will bring with it a stable Instant type.

I'll update the PR to use Instant tomorrow.

[canndrew]

Updated.

r? @vinipsmaker

[vinipsmaker]

Reviewed 13 of 13 files at r2.
Review status: all files reviewed at latest revision, all discussions resolved.

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