To get MaxTextureSize by using glGetIntegerv not by using environment variable

To get MaxTextureSize by using glGetIntegerv not by using environment variable

- Save MaxTextureSize in the gl-implementation after Context MakeCurrent
- Get it to the ImageLoader
- Use ConditionalWait to sync between two threads at the first time the DALi app is launching
- Save the MaxTextureSize that is supported at the GPU to a configuration file.
- After second launching of any DALi app, Adaptor read the configuration file without waiting.

Change-Id: I0d9bef5f59086c49c9d44ed6efdb1ae849c6f361
Signed-off-by: Seungho, Baek <sbsh.baek@samsung.com>