imporvements to uninitializedFill && initializeAll

Because they didn't really handle all of the cases correctly.

Added unittests.
"Ranges..." => "Needles..." in [starts|ends]With.
To avoid any confusion: The stuff in ranges may or may not actually be ranges. generic "Needles" is what best describes it.
Clean up endsWith unittests
Original author wrote "wrap" because filter is not bidirectional. However, the function filterBidirectional fits the need, so migrating to that.
Bit of unicode unittest in [starts|ends]With
Just sprinkling some tests. These covered a wee little bit of missing usecases.
Optimizations in startsWith
* Consolidate implementation by checking length in a single spot.
* Checks narrow string or the same types' lengths.
* Index iterates on all RA ranges (and not just Arrays).

Ends with was left untouched, because it forwards to startsWith anyways.
Optimization in startsWith(Range, Needles...)
Basically, makes it stop searching as soon as an element as matched.

This is an important optimization, that avoids a lot of startsWith's other "non-optimzations"...
std.array.join refactor.

tl;dr: std.array.join was quite complicated: 6 implementation functions, and a few hundred lines of code. Now it is just 2 functions, ~120 lines of code smaller, and within 10% performance of original (faster in some cases).

The original had 6 implementations: 3 joins with a separator, 3 without. For each, those 3 consisted of:
* A general slow version (uses `std.algorithm.joiner` with `appender`).
* A version for a range of arrays where you know the length (pre-allocates the destination array then uses array ops).
* A version for a range of arrays where you don't know the length (uses `appender`).

There's no need for the second version because you can just use appender and `.reserve` the size upfront. Appender already uses array ops when available in its `put` function.

There's also no need for the first function because using `joiner` is slower than just looping through the sub-ranges, appending them. The third function doesn't even use the fact that its operating on a range of arrays, so it can easily be merged with the first and second.

The end result is just one function for join with a separator, and one for a join without. They both use `appender`, and have a static branch that will `.reserve` the required size when the information is available.
Fix for mismatched string types + added unittests.
Convert sep to array for performance/generality.
Fix for non-array separators for non-string RoR.
fix issue 9211

A leftover from semantically incorrect optimization in std.regex
[style] various fixes found during review
More improvements and optimisations to array.join
[style] reindent
Merge pull request #1040 from blackwhale/regex-bug9211

Regex bugfix (issue 9211). I assume FreeBSD's failure is unrelated.
Fix previous bug in countUntil

as pointed out by denish-sh. Also, more unittests.
typo
Merge pull request #1042 from monarchdodra/countUntil2

Fix previous bug in countUntil
Set CA certificates of HTTP
indent