Fix std.traits for large input

std.traits: EnumMembers, isExpressionTuple, isTypeTuple & Largest balks
at large input
EnumMembers now works with single-member enums.
Merge branch 'master' of https://github.com/D-Programming-Language/phobos
fix Issue 10230 - Duplicated buttons for runnable examples
Merge remote-tracking branch 'upstream/master'
It appears that whoever changed the name of the range parameter to encode didn't rename the parameter everywhere in the function.
issue 10909 toImpl support for bool narrowing conversion. mostNegative support for bool.
Implement toString that supports %f.
Add deprecation date.

Improve documentation for new toString.
Changed an assert to a static assert, to cause an error at compile time rather than runtime,
Added a set of unit tests to ensure all branches of encode(E, R) get exercised.
Add unittest for issue 6381.

To prevent regressions.
Add TODO to make toString() pure @safe nothrow

I tried each of those qualifiers but none of them compiled due to the
way std.format works right now. So leave it for the future.
Merge pull request #1531 from quickfur/issue6381

Add unittest for issue 6381 (std.math.floor/ceil should be pure)
Undo some changes to work around bug. Oh well.
sidestep issue 10928
Merge pull request #1516 from quickfur/complex_format

Fix issue 10881: support writefln("%f") of complex numbers
Fix issue 10893: added missing or renamed DDoc parameters (found by fix to 10236)
Merge pull request #1328 from 9rnsr/fix10230

Issue 10230 - Duplicated buttons for runnable examples
Remove explicit qualifiers for translate overloads which take a buffer. Use std.range.put instead of member function put when writing to the buffer.