update documentation and help output for how to specify secrets on stdin

also update all examples to have no space after short option.

README

@@ -91,49 +91,46 @@ on exactly what happens --verbose or --verbose=2 may be added.
 Generate a new ECC-P256 key on device in slot 9a, will print the public
 key on stdout:
 
-  $ yubico-piv-tool -s 9a -A ECCP256 -a generate
+  $ yubico-piv-tool -s9a -AECCP256 -agenerate
 
 Generate a certificate request with public key from stdin, will print
 the resulting request on stdout:
 
-  $ yubico-piv-tool -s 9a -S '/CN=foo/OU=test/O=example.com/' -P 123456 \
-    -a verify -a request
+  $ yubico-piv-tool -s9a -S'/CN=foo/OU=test/O=example.com/' -averify -arequest
 
 Generate a self-signed certificate with public key from stdin, will print
 the certificate, for later import, on stdout:
 
-  $ yubico-piv-tool -s 9a -S '/CN=bar/OU=test/O=example.com/' -P 123456 \
-    -a verify -a selfsign
+  $ yubico-piv-tool -s9a -S'/CN=bar/OU=test/O=example.com/' -averify -aselfsign
 
 Import a certificate from stdin:
 
-  $ yubico-piv-tool -s 9a -a import-certificate
+  $ yubico-piv-tool -s9a -aimport-certificate
 
 Set a random chuid, import a key and import a certificate from a PKCS12
-file with password test, into slot 9c:
+file, into slot 9c:
 
-  $ yubico-piv-tool -s 9c -i test.pfx -K PKCS12 -p test -a set-chuid \
-    -a import-key -a import-cert
+  $ yubico-piv-tool -s9c -itest.pfx -KPKCS12 -aset-chuid -aimport-key \
+    -aimport-cert
 
 Change the management key used for administrative authentication:
 
-  $ yubico-piv-tool -n 0807605403020108070605040302010807060504030201 \
-    -a set-mgm-key
+  $ yubico-piv-tool -aset-mgm-key
 
-Delete a certificate in slot 9a:
+Delete a certificate in slot 9a, with management key being asked for:
 
-  $ yubico-piv-tool -a delete-certificate -s 9a
+  $ yubico-piv-tool -adelete-certificate -s9a -k
 
 Show some information on certificates and other data:
 
-  $ yubico-piv-tool -a status
+  $ yubico-piv-tool -astatus
 
 Read out the certificate from a slot and then run a signature test:
 
-  $ yubico-piv-tool -a read-cert -s 9a
-  $ yubico-piv-tool -a verify-pin -P 123456 -a test-signature -s 9a
+  $ yubico-piv-tool -aread-cert -s9a
+  $ yubico-piv-tool -averify-pin -atest-signature -s9a
 
 Import a key into slot 85 (only available on YubiKey 4) and set the
 touch policy (also only available on YubiKey 4):
 
-  $ yubico-piv-tool -a import-key -s 85 --touch-policy=always -i key.pem
+  $ yubico-piv-tool -aimport-key -s85 --touch-policy=always -ikey.pem