Delete renderer before gl context switch
Delete renderer before gl context switch

This way, gl state (e.g. fragment programs) are freed while
the correct context is current and glDeleteProgram won't
complain about invalid values

git-svn-id: a0a066a1d7ce87c7a04dae20f169ad0cd8bda35d@1066 04231f92-3938-0410-9931-e931ac552b4f

deskvox/deskvox,deskvox/deskvox,deskvox/deskvox,deskvox/deskvox,deskvox/deskvox