vi: modify group ư rules and phonemes

dictsource/vi_rules

         ưở         y@4
         ưỡ         y@5
         ượ         y@6
-        ưu         yw
+        ưu         iw
         ươi        y@j
         ười        y@j2
         ưới        y@j3
 .group ừ
         ừ          y2
         ừa         y@2
-        ừu         y2w2
+        ừu         iw2
         
  
         
 .group ứ
         ứ          y3
         ứa         y@3
-        ứu         y3w3
+        ứu         iw3
         
  
         
 .group ử
         ử          y4
         ửa         y@4
-        ửu         y4w4
+        ửu         iw4
         
  
         
 .group ữ
         ữ          y5
         ữa         y@5
-        ữu         y5w5
+        ữu         iw5
         
  
         
 .group ự
         ự          y6
         ựa         y@6
-        ựu         y6w6
+        ựu         iw6
         
  
         

phsource/ph_vietnam

 	length 136
   ELIF nextPhW(N) THEN
 	length 101
+  ELIF nextPhW(w) OR nextPhW(j) THEN 
+    length 110
   ELIF thisPh(isFirstVowel) AND thisPh(isFinalVowel) AND thisPh(isWordEnd) THEN
 	length 300
   ELIF thisPh(isFirstVowel) AND thisPh(isFinalVowel) AND thisPh(isWordStart) THEN
 	length 163
   ELIF nextPhW(N) THEN
 	length 115
+  ELIF nextPhW(w) THEN
+    length 100
   ELIF thisPh(isFirstVowel) AND thisPh(isFinalVowel) AND thisPh(isWordEnd) THEN
 	length 300
   ELIF thisPh(isFirstVowel) AND thisPh(isFinalVowel) AND thisPh(isWordStart) THEN
       length 100
     ENDIF
     FMT(vietnam/n^_)	
-  ElSE
+  ELSE
     FMT(n^/_n^)
   ENDIF
 endphoneme