Made core.thread import in std.file non-selective.

Bug# 314 just makes it create import conflicts when compiling with
-unittest. It works just as well (better given bug# 314) as a normal
import.
Removed typedef tests in std.conv.

Now that typedef has been deprecated, having it in std.conv's tests
results in any code which imports std.conv and builds with -unittest
having to build with -d, which is unacceptable IMHO. I don't like
getting rid of the tests, but they were passing, and presumably, the
overloads of std.conv.to which use typedef will be deprecated shortly as
well.
Deprecated overloads for std.conv.to which use typedef.
Updated changelog for deprecations in std.conv.to.
Minor fix to deprecation message on std.string.splitLines.

http://d.puremagic.com/issues/show_bug.cgi?id=6990
add missing import of std.stdio
Issue 6973 - static assert(isOutputRange!(OutputRange!int, int)) is false
fix 32 vs 64bit-ism in bituintcore.d
enable std.conv tests on 64 bit platforms.. seems to pass on linux now
Fix for 7039 | http://d.puremagic.com/issues/show_bug.cgi?id=7039 | Posix 2.057 Makefile error breaking 64bit build
Fix for 7039 | fixed "typo"
Size optimisation of std.datetime (saves 12KB)

Large switch statements have been replaced by data-driven array lookups to reduce the amount of code generated and also improve performance. Using DMD 2.056 on OSX x86 this cuts 12KB off of a Hello World program.

The motivation for this change is to try and reduce the size of small D programs as their large size is a common (and valid) complaint amongst newcomers.
Issue 6979 - hasUnsharedAliasing cannot accept plural parameters
std.regex: assertion on wrong escapes inside []

also enable extra test in std.internal.uni
More conservative alignment check in ShiftOr
Missing assert with the same alignment check
std.math: Fix modf() documentation, add fmod()

The documentation for std.math.modf() actually describes the fmod()
function of C's math.h, which doesn't have a counterpart in std.math.
This commit adds fmod() and fixes the documentation for modf().

This fixes issue 4765.
Issue 7055 - to!float("INF2") == 2
Use D_LP64 to make bitness-based decisions, not X86(_64).
Drop unnecessary version statement and use size_t.sizeof * 8 instead.