Add freetype.framework and edit CMake accordingly. (Close #241)

Freetype version 2.4.11, build for OS X 10.5 and above as universal
binary (i386 + x86_64)

extlibs/libs-osx/Frameworks/freetype.framework/Resources

@@ -0,0 +1 @@
+Versions/Current/Resources

extlibs/libs-osx/Frameworks/freetype.framework/Versions/A/Resources/Info.plist

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>English</string>
+	<key>CFBundleExecutable</key>
+	<string>freetype</string>
+	<key>CFBundleIdentifier</key>
+	<string>org.sfml-dev.freetype</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundlePackageType</key>
+	<string>FMWK</string>
+	<key>CFBundleSignature</key>
+	<string>????</string>
+	<key>CFBundleVersion</key>
+	<string>1.0</string>
+</dict>
+</plist>

extlibs/libs-osx/Frameworks/freetype.framework/Versions/Current

@@ -0,0 +1 @@
+A

extlibs/libs-osx/Frameworks/freetype.framework/freetype

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+Versions/A/freetype