Clean up "allow to"

* README, cipher/cipher.c, cipher/pubkey.c, doc/gpg.texi: replace
  "allow to" with clearer text

In standard English, the normal construction is "${XXX} allows ${YYY}
to" -- that is, the subject (${XXX}) of the sentence is allowing the
object (${YYY}) to do something.  When the object is missing, the
phrasing sounds awkward, even if the object is implied by context.
There's almost always a better construction that isn't as awkward.

These changes should make the language a bit clearer.

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>

README

@@ -632,7 +632,7 @@
                     is in general the preferable solution.  However
                     the code is new and under some cirumstances it may
                     give different output than with the limited old
-                    support.  This option allows to explicity disable
+                    support.  This option explicitly disables
                     the use of iconv.  Note, that iconv is also
                     disabled if gettext has been disabled.
 

cipher/cipher.c

@@ -586,7 +586,7 @@ do_cfb_encrypt( CIPHER_HANDLE c, byte *outbuf, byte *inbuf, unsigned nbytes )
 
   /* Now we can process complete blocks.  We use a loop as long as we
      have at least 2 blocks and use conditions for the rest.  This
-     also allows to use a bulk encryption function if available.  */
+     also allows use of a bulk encryption function if available.  */
 #ifdef USE_AES
   if (nbytes >= blocksize_x_2 
       && (c->algo == CIPHER_ALGO_AES
@@ -677,7 +677,7 @@ do_cfb_decrypt( CIPHER_HANDLE c, byte *outbuf, byte *inbuf, unsigned nbytes )
   
   /* Now we can process complete blocks.  We use a loop as long as we
      have at least 2 blocks and use conditions for the rest.  This
-     also allows to use a bulk encryption function if available.  */
+     also allows use of a bulk encryption function if available.  */
 #ifdef USE_AES
   if (nbytes >= blocksize_x_2 
       && (c->algo == CIPHER_ALGO_AES

cipher/pubkey.c

@@ -276,7 +276,7 @@ check_pubkey_algo2( int algo, unsigned use )
     int i;
 
     /* Map type 20 Elgamal algorithm to type 16 if it is used for
-       decryption.  This allows to use legacy type 20 Elgamal keys for
+       decryption.  This allows use of legacy type 20 Elgamal keys for
        decryption.  */
     if (algo == PUBKEY_ALGO_ELGAMAL && use == PUBKEY_USAGE_ENC)
       algo = PUBKEY_ALGO_ELGAMAL_E;

doc/gpg.texi

@@ -1211,7 +1211,7 @@ Use @code{file} to access the smartcard reader. The current default is
 @item --disable-ccid
 @opindex disable-ccid
 Disable the integrated support for CCID compliant readers. This
-allows to fall back to one of the other drivers even if the internal
+allows falling back to one of the other drivers even if the internal
 CCID driver can handle the reader. Note, that CCID support is only
 available if libusb was available at build time.
 
@@ -1438,7 +1438,7 @@ mechanisms, in the order they are to be tried:
   may be used here to query that particular keyserver.
 
   @item local
-  Locate the key using the local keyrings.  This mechanism allows to
+  Locate the key using the local keyrings.  This mechanism allows the user to
   select the order a local key lookup is done.  Thus using
   @samp{--auto-key-locate local} is identical to
   @option{--no-auto-key-locate}.
@@ -2416,7 +2416,7 @@ to display the message. This option overrides @option{--set-filename}.
 @itemx --no-use-embedded-filename
 @opindex use-embedded-filename
 Try to create a file with a name as embedded in the data. This can be
-a dangerous option as it allows to overwrite files. Defaults to no.
+a dangerous option as it enables overwriting files. Defaults to no.
 
 @item --cipher-algo @code{name}
 @opindex cipher-algo