pango-render: set CLAMP_TO_EDGE wrap mode on glyph_material
pango-render: set CLAMP_TO_EDGE wrap mode on glyph_material

The pango renderer was causing lots of override materials to be allocated
because the vertex_buffer API converts AUTOMATIC mode into REPEAT for
backwards compatibility. By explicitly setting the wrap mode to
CLAMP_TO_EDGE when creating the glyph_material then the vertex_buffer
API will leave it untouched.

Distrotech/cogl,djdeath/cogl-android,Distrotech/cogl,djdeath/cogl-android,spatulasnout/cogl,gcampax/cogl,djdeath/cogl,Distrotech/cogl,djdeath/cogl,gcampax/cogl,spatulasnout/cogl,gcampax/cogl,djdeath/cogl-android,Distrotech/cogl,gcampax/cogl,djdeath/cogl,collects/cogl,collects/cogl