Add --print as an alias for -P, to match tcpdump.

tcpdump just got a --print option, which causes packet information to be
printed even if the raw packets are being saved to a file with -w.  We
have -P for the same purpose; make --print another name for it.

While we're at it:

	document --help and --version;

	just speak of -P/--print as causing printing even of the packet
	details, even though -V forces printing with -w, for consistency
	with how --print is documented for tcpdump;

	fix the description of -h/--help.

Change-Id: Idf650a202a09a2d1682edbd9d76123f1b1412b55
Reviewed-on: https://code.wireshark.org/review/23888
Reviewed-by: Guy Harris <guy@alum.mit.edu>

doc/tshark.pod

@@ -500,7 +500,9 @@ the type of record.
 
 =item -h
 
-Print the version and options and exits.
+=item --help
+
+Print the version and options and exit.
 
 =item -H  E<lt>input hosts fileE<gt>
 
@@ -659,8 +661,10 @@ promiscuous mode.
 
 =item -P
 
-Decode and display the packet summary, even if writing raw packet data using
-the B<-w> option.
+=item --print
+
+Decode and display the packet summary or details, even if writing raw
+packet data using the B<-w> option.
 
 =item -q
 
@@ -835,6 +839,8 @@ Enter an empty tap name "" to get a list of available names.
 
 =item -v
 
+=item --version
+
 Print the version and exit.
 
 =item -V

tshark.c

@@ -676,6 +676,7 @@ main(int argc, char *argv[])
     {"version", no_argument, NULL, 'v'},
     LONGOPT_CAPTURE_COMMON
     LONGOPT_DISSECT_COMMON
+    {"print", no_argument, NULL, 'P'},
     {"export-objects", required_argument, NULL, LONGOPT_EXPORT_OBJECTS},
     {"color", no_argument, NULL, LONGOPT_COLOR},
     {"no-duplicate-keys", no_argument, NULL, LONGOPT_NO_DUPLICATE_KEYS},