Add warnings for numeric string keys when reading from intmap

Reviewed By: @paroski

Differential Revision: D1430008
Add warnings for calls to sort on intmaps

Summary: Change dispatch in g_array_funcs of Sort and Usort to WarnAndSort and
WarnAndUsort respectively. This way we don't incur any overhead for regular
kMixedKind arrays.

Reviewed By: @paroski

Differential Revision: D1429736
don't fail test if intl is too old

Summary: This is failing on cmake builds and anoying me in the oncall email

Reviewed By: @JoelMarcey

Differential Revision: D1432980
Fix build broken on OS X

Summary: Typo fix, rename `dest` to `reg` to match GCC_FAST_TLS version

This closes issue #3145
Closes #3159
Created from: https://github.com/facebook/hhvm/pull/3159

Reviewed By: @markw65

Differential Revision: D1428182
Correct a config key name in debugger.devdocs

Summary: It's "Eval.Debugger.Port", not "Eval.Debugger.DebugggerServerPort".
Closes #3186
Created from: https://github.com/facebook/hhvm/pull/3186

Reviewed By: @ptarjan

Differential Revision: D1435399
Enable sorting for Sets

Summary: Now that Sets retain insertion order it would be handy if Sets could be
sorted using PHP's sort builtin functions. This diff leverages to shared
implementation between Map and Set to enable sorting for Sets.

Reviewed By: ptc, eletuchy

Differential Revision: D1435214
Turn on the rest of the numeric string key warnings

Reviewed By: @paroski

Differential Revision: D1430084
Improved PHP5 compatibility for the image extension.

Summary: * Added ICO support to `getimagesize()`. This fixes #2985.
 * Added BITMAPV5HEADER support to `getimagesize()`.
 * Removed superfluous warning in `getimagesize()`.
 * Fixed handling of `imageinfo` argument in `getimagesize()`.
 * Fixed the bmp mimetype.
 * Added missing test fixtures.
Closes #3080

Reviewed By: @LiraNuna

Differential Revision: D1427298
Call $this->__init__() even in native classes

Summary: We (WMF) have many classes that look like:

```
<<__NativeData("ZendCompat")>>
class LuaSandboxError extends Exception {}
```

Native::nativeDataInstanceCtor() is mostly a duplicate of
ObjectData::newInstance(), but the Native function inappropriately omits
the \_\_init__() call. So for the test case above, the exception trace is
not initialised.

Fix this, and also give a more informative error message when
Exception::\_\_init__() is not called prior to
Exception::getTraceAsString().
Closes #3088
Created from: https://github.com/facebook/hhvm/pull/3088

Reviewed By: @swtaarrs

Differential Revision: D1435376