weston-ivi-shell: Fix illegal surface free.

Signed-off-by: Nobuhiko Tanibata <NOBUHIKO_TANIBATA@denso.co.jp>
cmake: Add gl libraries.

Signed-off-by: Nobuhiko Tanibata <NOBUHIKO_TANIBATA@denso.co.jp>
weston-ivi-shell: Add function of save as bitmap.

Signed-off-by: Nobuhiko Tanibata <NOBUHIKO_TANIBATA@denso.co.jp>
weston-ivi-shell: Add surface-screenshot function.

Signed-off-by: Nobuhiko Tanibata <NOBUHIKO_TANIBATA@denso.co.jp>