Revert "More 10.7 -> 10.9 bumps"

This reverts commit 24a4360600.

builds/Makefile

@@ -1828,7 +1828,7 @@ LLVM_BASE_CONFIGURE_ENVIRONMENT=$(COMMON_ACVARS)
 	@echo "Configuring llvm"
 	@cd llvm && \
 	$(LLVM_BASE_CONFIGURE_ENVIRONMENT) \
-	$(abspath $(LLVM_PATH)/configure) --prefix=$$PWD/usr --build=i386-apple-darwin10.9  --enable-targets="arm" $(LLVM_BASE_CONFIGURE_FLAGS) --cache-file=../llvm.config.cache CC="$(CCACHE)clang" CXX="$(CCACHE)clang++" CXXFLAGS="$(LLVM_CXXFLAGS)" > $@.log 2>&1 || (echo "Configuring llvm failed:" && cat $@.log | sed "s/^/    /" && exit 1)
+	$(abspath $(LLVM_PATH)/configure) --prefix=$$PWD/usr --build=i386-apple-darwin10.7  --enable-targets="arm" $(LLVM_BASE_CONFIGURE_FLAGS) --cache-file=../llvm.config.cache CC="$(CCACHE)clang" CXX="$(CCACHE)clang++" CXXFLAGS="$(LLVM_CXXFLAGS)" > $@.log 2>&1 || (echo "Configuring llvm failed:" && cat $@.log | sed "s/^/    /" && exit 1)
 	$(Q) @touch $@
 	@echo Configured llvm
 

tools/mmp/Application.cs

@@ -15,7 +15,7 @@ namespace Xamarin.Bundler {
 		internal void Initialize ()
 		{
 			if (DeploymentTarget == null) 
-				DeploymentTarget = new Version (10, 9);
+				DeploymentTarget = new Version (10, 7);
 		}
 
 		void SelectRegistrar ()