Jetted en and ex

You'll note that ex involves more endianness twiddling. This is
unfortunate, but en is exactly as stupid as you'd hope it would be,
so I'm going to call it okay.

Also, fixed ex. In particular, (ex:aesc 0) now agrees with the C's
output. Our bad.

arvo/hoon.hoon

@@ -4228,7 +4228,7 @@
   |%                                                    ::  user-facing arms
   ++  be                                                ::  block cipher
     ~/  %be
-    |=  [a=? b=@ c=@H]
+    |=  [a=? b=@ c=@H]  ^-  @uxH
     ~|  %be-aesc
     =>  %=    .
             +
@@ -4275,10 +4275,10 @@
     =>  .(e (sark e (ankh d nnr b)))
     (rep 5 e)
   ++  en                                                ::  AES block en
-    ::  ~/  %en
-    |=([a=@I b=@H] (be & (ex a) b))
+    ~/  %en
+    |=([a=@I b=@H] ^-(@uxH (be & (ex a) b)))
   ++  ex                                                ::  key expand
-    ::  ~/  %ex
+    ~/  %ex
     |=  a=@I  ^-  @
     =+  [b=a c=0 d=su:fort i=nnk]
     |-
@@ -4293,11 +4293,11 @@
           .(c (sube c d))
         .
     =>  .(c (mix c (cut 5 [(sub i nnk) 1] b)))
-    =>  .(b (cat 5 b c))
+    =>  .(b (can 5 [i b] [1 c] ~))
     $(i +(i))
   ++  in                                                ::  AES block de
     ::  ~/  %in
-    |=([a=@I b=@H] (be | (ix (ex a)) b))
+    |=([a=@I b=@H] ^-(@uxH (be | (ix (ex a)) b)))
   ++  ix                                                ::  key expand, inv
     ::  ~/  %ix
     |=  a=@  ^-  @