killer messages

Incorporate various killer message grammar fixes suggested by <Someone>.
Mostly these deal with using the proper killer_format and prefix ("the" or
no "the") for unique and type_is_pname monsters, or death to to eating
their corpses.
One case is handled by a general fix to name_to_mon to allow it to deal
with "Croesus' corpse".
The pre-3.4.1 topten behavior for "starved to death" messages is also restored.

src/mondata.c

@@ -468,6 +468,10 @@ const char *in_str;
 			(str[m_i_len] == ' ' ||
 			 !strcmpi(&str[m_i_len], "s") ||
 			 !strncmpi(&str[m_i_len], "s ", 2) ||
+			 !strcmpi(&str[m_i_len], "'") ||
+			 !strncmpi(&str[m_i_len], "' ", 2) ||
+			 !strcmpi(&str[m_i_len], "'s") ||
+			 !strncmpi(&str[m_i_len], "'s ", 3) ||
 			 !strcmpi(&str[m_i_len], "es") ||
 			 !strncmpi(&str[m_i_len], "es ", 3))) {
 		    mntmp = i;