add ELSE-IF … THEN-IF, other minor words, and cleanup

test/multi-if.4th

@@ -0,0 +1,10 @@
+: TEST
+   DUP . ": " TYPE
+   DUP 1 = IF "1\n" TYPE
+   ELSE-IF DUP 2 = THEN-IF "2\n" TYPE
+   ELSE-IF DUP 0<= THEN-IF "nonpositive\n" TYPE
+   ELSE-IF DUP 5 <= THEN-IF "3…5\n" TYPE
+   ELSE "other\n" TYPE
+   THEN DROP ;
+
+{ 7 0 ?DO I TEST LOOP } EXECUTE

test/multi-if.exp

@@ -0,0 +1,8 @@
+0: nonpositive
+1: 1
+2: 2
+3: 3…5
+4: 3…5
+5: 3…5
+6: other
+exit-code: 0

test/numeric-literals.4th

@@ -1,4 +1,6 @@
+ALSO UTILITY
 : INSPECT ( c-addr u -- ) "\"" TYPE TYPE-ESCAPED "\"" TYPE ;
+PREVIOUS
 
 : REPORT ( c-addr1 u1 c-addr2 u2 xt -- )
    -ROT 2>R >R 2DUP INSPECT " ( " TYPE EVALUATE DUP R@ EXECUTE " ) ⇔ " TYPE