Merge pull request #2205 from jmdavis/datetime

Converted more of std.datetime's examples to ddoc-ed unit tests.
add NullSink output range
Merge pull request #2030 from WalterBright/add-BitBucket2

add BitBucket output range
fix Issue 7822 - lseek cast(int)offset should be lseek cast(off_t)offset
Make BigInt nothrow where possible
Merge pull request #2209 from SerialVelocity/master

Fix Issue 7822 - lseek cast(int)offset should be lseek cast(off_t)offset
more operators nothrow
fix import declarations
Merge pull request #2211 from 9rnsr/fix12359

fix import declarations
Mark std.stdio.File.seek as @trusted
Merge pull request #2214 from tom-tan/trusted-stdio-File-seek

Mark std.stdio.File.seek as @trusted
Merge pull request #2210 from dymk/bignum-nothrow

Make BigInt nothrow where possible
Fix issue 12828: Fix return type of SimpleTimeZone.utcOffset.