Add yesstr and nostr for doi_IN, kok_IN, and sat_IN

	For the locales doi_IN,  kok_IN, and sat_IN, the words for
	“yes” and “no” were apparently in yesexpr and noexpr.
	Copy them from there to add yesstr and nostr.
	Also make yesexpr and noexpr more readable by using
	the POSIX portable character set.

	* locales/doi_IN (LC_MESSAGES): Add yesstr and nostr.
	* locales/kok_IN (LC_MESSAGES): Add yesstr and nostr.
	* locales/sat_IN (LC_MESSAGES): Add yesstr and nostr.