Add basic support for OSX build

qmapboxgl.pro

@@ -1,3 +1,7 @@
+# Note: remember to keep these versions up to date.
+LIBUV_VERSION=0.10.28
+SQLITE_VERSION=3.8.8.1
+
 SUBDIRS = example
 
 QT += widgets
@@ -6,6 +10,35 @@ TEMPLATE = app
 
 CONFIG += link_pkgconfig opengl c++11 debug
 
+macx {
+    !system(which mason >/dev/null) {
+        MASON_URL=https://github.com/mapbox/mason installation
+        error(Mason not found; Please follow the installation steps in $$join(MASON_URL, $$LITERAL_HASH))
+    }
+
+    message(Checking for libuv $$LIBUV_VERSION ...)
+    !system(mason install libuv $$LIBUV_VERSION >/dev/null) {
+        error(unable to install libuv $$LIBUV_VERSION - please check your internet connection)
+    }
+
+    message(Checking for sqlite $$SQLITE_VERSION ...)
+    !system(mason install sqlite $$SQLITE_VERSION >/dev/null) {
+        error(unable to install sqlite $$SQLITE_VERSION - please check your internet connection)
+    }
+
+    # Qt disables pkg-config by default on OSX.
+    QT_CONFIG -= no-pkg-config
+
+    # MapboxGL static libs depends on these specific dependency versions.
+    LIBS += \
+        $$system(mason ldflags libuv 0.10.28) \
+        $$system(mason prefix libuv 0.10.28)/lib/libuv.a \
+        $$system(mason ldflags sqlite 3.8.8.1) \
+        $$system(mason prefix sqlite 3.8.8.1)/lib/libsqlite3.a \
+        -framework Foundation \
+        -framework ApplicationServices
+}
+
 PKGCONFIG += libmbgl
 
 SOURCES += example/example.cpp \