GUACAMOLE-470: Support named colors in color-scheme configuration.

When parsing named colors, treat semi-colons as string terminators, so
we can properly parse named colors within the color-scheme
configuration.

src/terminal/named-colors.c

@@ -761,8 +761,13 @@ static int guac_terminal_named_color_search(const void* a, const void* b) {
         /* Skip any spaces in key (name will never have spaces) */
         while (*key && isspace(*key)) key++;
 
+        /* Treat semi-colon as string terminator, to support parsing color
+           names within a larger string (e.g. within the terminal color-scheme
+           configuration string). */
+        const int keyChar = (*key == ';') ? '\0' : tolower(*key);
+
         /* Compare, ignoring case (name is already known to be lowercase) */
-        int difference = tolower(*key) - *name;
+        int difference = keyChar - *name;
         if (difference)
             return difference;