Migrate weston 1.4.91 later.

Due to the change of folder structure, previous source can not be built with 1.4.91 later.

Signed-off-by: Nobuhiko Tanibata <NOBUHIKO_TANIBATA@xddp.denso.co.jp>
Fix memory access violations.
Fix a lock issue when the API tests is running.

Signed-off-by: Nobuhiko Tanibata <NOBUHIKO_TANIBATA@xddp.denso.co.jp>
Throw exception if wl_display_roundtrip returns error.