Rewrite of Phobos index page.

Make it more useful than the current outdated and irrelevant philosophy
page.
Remove useless link to obsolete wiki.
Move last paragraph to top for easier reading.
Fix broken ddoc build for std/regex/package.d.
Update std.range.* docs.

The previous docs were simply dissected from the original std.range docs, and
the text in each module is truncated and awkward to read. The main package.d
docs were also missing links to the submodules. So, update the docs to reflect
the current state of things.
Fix broken PHOBOSSRC link.

This is caused by Ddoc's "helpful" auto-highlighting of every occurrence of the
name of the module, including places where it's not very helpful.
Don't import std.format in any public scope.

Workaround for: https://issues.dlang.org/show_bug.cgi?id=13808
allow casting Typedef to another Typedef
Add missing imports
Merge pull request #2783 from 9rnsr/fix_imports

Add missing imports
Merge pull request #2780 from quickfur/issue13808

Issue 13808: Don't import std.format in any public scope.
fix issue 11434
added version(Posix) to unittest
disable fiber test on win32
Issue 9507: transposed() behaves poorly with jagged range of ranges
Merge pull request #2785 from braddr/win32_2012

disable fiber test on win32
Merge pull request #2786 from quickfur/issue9507

Issue 9507: transposed() behaves poorly with jagged range of ranges
Fix issue 12589 - std.random.randomCover fails for empty ranges
Remove redundant initialization
Update std.container docs to reflect new submodules.

Improve wording in std.container docs.