[python] mac pip install pil / brew install pil

之前使用mac 在install pip 一些出現某先錯誤，某些xcode 的lib錯誤。

In file included from _imagingtk.c:19:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include/tk.h:78:11: fatal error:
      'X11/Xlib.h' file not found
#       include <X11/Xlib.h>
                ^
1 error generated.
error: Setup script exited with error: command 'cc' failed with exit status 1



pc_liao@IronMan[~/code/]{16:18}
$ xcode-select --install
xcode-select: note: install requested for command line developer tools

後就可以順利 install 完。