Fix a build error on linux platforms

Due to dl* function usage in Core/HW/atrac3plus.cpp on non-windows
platforms, Core library needs to be linked with -ldl flag on these
platforms.

Added a CoreExtraLibs variable in CMakeLists.txt to handle all
platform-dependent dependencies of Core, and added dl to this variable
on non-win32 platforms.
Use CMAKE_DL_LIBS instead of dl
Modified the dl link flag to linux platform only
Improve PSP system dialogs' looks.
Format date according to configurations.
Swap positions of button tips.
Fix text wrapping with non-top-left text alignment.
Auto-height the "borders" of the message text area.
More dialog tweaks.
Unify some common elements of dialogs.
Merge pull request #2124 from chaserhkj/linux-fix

Fixed a build error on non-win32 platfroms
Use Button X to Confirm option also changes osk select and delete buttons
Merge pull request #2202 from evilcorn/master

Use Button X to Confirm option changes osk select and delete buttons
Add STATE_SUSTAIN code similar to JPCSP, should fix sound fx again in some games.
Please comment in the github commit if this breaks anything. Fixes #2189
Update native, fixing bug that prevented plugin downloads from working on Android. Fix black background.t
Add option to have PPSSPP stay on top of other windows. Fixes #2199
Fix crash when clicking UI early. Fixes #2196
Work-around crash in sceMpeg with bad ringbuffer address.
Add reminder on first run to access the ingame menu with ESC on windows.
Add fixes to sceMpegAvcDecodeYCbCr().

It seems a lot like sceMpegAvcDecode(), these are just copy/paste.
Allow a video end a couple packets from end.

Fixes #2206, Patapon 3.  Possibly we don't even need this check at all,
but I'm not sure.
Merge pull request #2207 from unknownbrackets/mpeg-fix

Allow an mpeg to finish even not completely at stream end
Cleanup some SAS constructors.
sceSasInit() ignores maxVoices and always does 32.

Weird, I can't find anything that parameter does except generate errors.
Most games call with 32 anyway...

Affects only sceSasGetEndFlag() and sceSasGetPauseFlag() really.
Fix some crash in debug builds.