Added Xcode 4 build projects

Requires the Photoshop CC SDK, placed at ext/photoshopsdk

This is only building on x64 because right now our 32-bit dialogs for
Mac use ADM, which is gone in this SDK.
Pulling in windows fixes
Merge project tweak
Ditch Target setting
Add Xcode 5 projects

Uses OS X SDK 10.9
Merge slider feedback
Upgraded project settings
Add search path for PS SDK
Hack HIToolbox search path
Merge pull request #2 from pornel/xcode4

Xcode 5 (and 6) tweaks
Return Xcode 3 projects back to previous state
Merge work from pngquant branch
Get Kornel's name into Korel's branch
Getting pngquant submodules
Pull in bug fix and other stuff
Add USE_SSE on Xcode 5

Verified that this is the same as USE_SSE=1
Add NDEBUG to release builds

To keep the asserts quiet.
Added USE_SSE and NDEBUG to Xcode 4 projects

Must be my OCD, because I don't think anyone cares about these.
Pull in dialog changes etc
Merge branch 'xcode4'

Bringing the Xcode 4 and 5 projects into the Master branch.  The build we distribute is made with Xcode 3 and the CS5 SDK, because that's the only one that does ppc, i386, and x86_64 targets together. For the Xcode4 and 5 projects, get the Photoshop CC SDK.