[OSX] New fast mac 5.1 build

This should work for OS X 10.9+ Have tested on 10.11, 10.12
This build addresses the couple of mac issues [OSX] Cairo Font Bug (RT Crashes when I open certain tiff or jpeg) · Issue #3899 · Beep6581/RawTherapee · GitHub Cairo Font Crash 5.1 crash in macOS 10.12.5 if .app renamed · Issue #3882 · Beep6581/RawTherapee · GitHub Renaming App Problem, and is using the -O3 optimizer flag and Open MultiProcessor support. Known issue: intermittent crash when quitting program after editing image.

https://filebin.net/fpn3joegylydvr3x/RawTherapee_OSX_10.9_64_5.1.zip

Version: 5.1
Branch: 5.1
Commit: f23d70fd
Commit date: 2017-05-15
Compiler: clang-mp-3 3.9.1
Processor: generic x86
System: Apple
Bit depth: 64 bits
Gtkmm: V3.16.0
Build type: release
Build flags: -arch x86_64 -O3 -std=c++11 -mtune=generic -Werror=unused-label -mmacosx-version-min=10.9 -flto -fopenmp=libomp -Werror=unknown-pragmas -Wall -Wno-unused-result -Wno-deprecated-declarations -O3 -DNDEBUG
Link flags:  -mtune=generic -headerpad_max_install_names -flto
OpenMP support: ON
MMAP support: ON