* Made emplace faster and replaced calls to it to also make them faster.
* Replaced phobos.d in posix.mak with index.d.
* Added version=StdDdoc to documentation build in posix.mak, and replaced uses of D_Ddoc with it.
* Improved documentation target in posix.mak (target dir automatically created).
* Added nice documentation table and cheat sheet at the top of std.algorithm.
* Replaced a few helper structs in std.range and std.algorithm with local structs, which simplify matters a fair amount.
* Added more constraints to functions in std.algorithm (still work in progress).
* Improved error message in std.algorithm.sort in case of failure to sort.
* std.random.dice(1, 10) now works (no need for array notation std.random.dice([1, 10])).
* Fixed documentation bugs and insufficiencies in std.range (still more to do).
* Improved speed of walkLength.
* Simplified retro.
* Simplified and optimized stride. Also folded stride(stride(r, a), b) into stride(r, a * b).
* Added roundRobin to std.range, which as a perk simplified radial.
* Added takeOne and takeNone to std.range.
* Added unsigned to std.traits.
* formatValue() deals with null, and delegates the actual work to private formatRange() added in this commit.
* Removed the isSomeString!T constraint of formatRange() because strings are already filtered out by formatValue().
Removed buffer arg from std.xml.encode since most of the time the data is string data, and the buffer was defined as the same type.
Fixed std.format unittests to not use string-based appenders, since they now cannot be rewritten.
std.algorithm: defined move with one argument; levenshtein distance generalized to with all forward ranges; take now has swapped arguments
std.array: empty for arrays is now a @property; front and back for a string and wstring automatically decodes the first/last character; popFront, popBack for string and wstring obey the UTF stride
std.conv: changed the default array formatting from "[a, b, c]" to "a b c"
std.range: swapped order of arguments in take
std.stdio: added readln template
std.variant: now works with statically-sized arrays and const data
std.traits: added isNarrowString