Merge audio capture work back into the mainline.

Patched to compile.

alsa: Implemented hotplug support, cleaned up device names.

ios: patched to compile.

alsa: don't enumerate virtual devices, just physical hardware.

Added SDL_PrivateJoystickAdded() and SDL_PrivateJoystickRemoved() Updated the removal code to iterate over all joystick add messages instead of just the first one.

commit 1170112da3776fdb06425f62d57b63144c33dc51 Author: James Zipperer <james.zipperer@synapse.com> Date: Sun Aug 21 01:19:19 2016 -0700 bugfix for controller / joystick add / remove being in the event queue at the same time

Emscripten: Fixed crash if closing removed joystick (thanks, Sylvain!).

Android: Fixed crash if closing removed joystick (thanks, Sylvain!). Fixes fix for Bugzilla #3408.

WinRT: fixed bug where Win10 GameBar, when shown + hidden, might not restore a cursor's hidden state The repro steps were this: 1. run an sdl2 winrt/uwp app, on Win10, v10.0.10586.0 or higher 2. hide the cursor, via a call to SDL_ShowCursor(0) 3. make the Win10 game bar appear, by pressing the Windows + G hotkey 4. observe that the mouse cursor appears, in order to interact with the game bar (this is expected behavior) 5. make the Win10 game bar disappear, either by pressing the Windows + G hotkey again, or clicking somewhere in the app EXPECTED RESULT: cursor disappears, as game bar disappears ACTUAL RESULT: cursor didn't always disappear

Added link in header comment.

Emscripten: Fixed opening previously closed joystick.

Android: Fixed opening previously closed joystick (thanks, Sylvain!). Fixes Bugzilla #3408.

[ OSX ] enables Xbox One S Guide (System Main Menu) button detection. the one possible impact is that since button identifiers on OSX are just their sequence in the HID report descriptor we might change the button order, and any existing/saved mappings may get their order changed.

Add Xbox One controller GUIDs to the XInput filter in the DirectInput joystick driver. The Windows 10 Anniversary Update (1607) breaks the method uses that SDL uses to detect XInput devices. That is, on Windows 10 Anniversary Update, it is no longer possible to query RAWINPUT for HID devices, and check for "IG_" in the device name. Presumably, this will be fixed in the future. This patch works around the issue by adding the Xbox One controller series to the well-known device list. This skips the more expensive RAWINPUT check for those devices, and causes them to be detected as XInput devices once again.

Fixed two old identifiers in header comments.

PSP: Fixed memory leak if video init failed.

WinRT: Removed not needed SDL_zerop() after SDL_calloc(). SDL_calloc() already sets memory to zero.

Added brackets to function names in header comments so that doxygen links them.

testaudiocapture: ask for way more output samples. Fixes Emscripten builds on Chrome for Android.

emscripten: send fake mouse events for touches, like other targets do. (This really should be handled at the higher level and not in the individual targets, but this fixes the immediate bug.)

emscripten audio: check for an "undefined" object, remove some console.log().

audio: Cleaned up "extern AudioBootStrap" list.

audio: Renamed some internal driver symbols in various targets.

android: implement audio capture support.

directsound: Implemented audio capture support.

windows: directsound should also map audio device GUIDs to proper names. Moved this code from winmm into core so both can use it. DirectSound (at least on Win10) also returns truncated device names, even though it's handed in as a string pointer and not a static-sized buffer. :/

audio: Patched to compile on C89 compilers.

emscripten audio: fix timer on capture's silence callback.

directsound: recalculate audiospec size before creating secondary buffer. I think this was a bug before? Maybe I'm misunderstanding this, but it looks like it was working because we allocate room for 8 chunks...