Add default arguments in cogl_texture_new_*
Add default arguments in cogl_texture_new_*

In many case of usage about cogl_texture_new_*, flags and format are used
as COGL_TEXTURE_NONE and COGL_PIXEL_FORMAT_ANY.

So it is better that they are optional arguments.

Signed-off-by: Emmanuele Bassi <049ee2061f71220e5aaf33f5be422fc2a2b06a44@linux.intel.com>

pmarti/pyclutter,pmarti/pyclutter,GNOME/pyclutter,pmarti/pyclutter,GNOME/pyclutter,pmarti/pyclutter