chk_common_scripts: LIBQUVI_SCRIPTS_DIR: Treat as a list of directories
chk_common_scripts: LIBQUVI_SCRIPTS_DIR: Treat as a list of directories

Treat LIBQUVI_SCRIPTS_DIR environment variable value as a list of
directories, each separated by a colon or a comma, depending on the
platform.

LIBQUVI_SCRIPTS_DIR should no longer be treated as an exclusive setting,
or in other words: continue the search even if it is set.

legatvs/libquvi,legatvs/libquvi,legatvs/libquvi