Update in chunks

reduces requirements to ForwardRange
Fix std.BigInt bug #9548 plus other new discovered bugs.
use default MODEL unless explicitly specified
Fixed regex loop-back stream to start from the correct position
Use ddoc-ed unittest feature
fix Issue 9976 - Needlessly large instantiation depth in std.typetuple algorithms
Merge branch 'master' of https://github.com/D-Programming-Language/phobos
Fixed a bunch of off-by-one errors in the regex code
Remove unnecessary default arguments
fixed receiveTimeout to not wait beyond the specified limit in the event of multiple internal waits
Make UTC and LocalTime singletons be instantiated with CTFE.

Yay! It's now possible to instantiate classes at compile time and then
use them at runtime.
Removed unused stream abstraction
bigint purity
Merge branch 'master' into bigintpure

Conflicts:
	std/bigint.d
bigint pure

the only exception is toString as it takes a delegate and this makes
things more tricky
Merge pull request #1287 from burner/bigintpure

BigInt pure Fixed issus #6850
Fix some borkage with documentation of File.readln variants; add a better example for File.readln(buf) that emphasizes the need to copy the buffer, since it is overwritten when read
Merge pull request #1284 from jmdavis/ctfe

Make UTC and LocalTime singletons be instantiated with CTFE.
Merge pull request #1279 from complexmath/fix_receiveTimeout

Fixed an issue where receiveTimeout might wait too long
Merge pull request #1288 from MrTact/master

Update to std.stdio documentation for File.readln variants