Mention the --help command line option in the documentation.

Bug-Debian: https://bugs.debian.org/517257
diff --git a/bzip2.1 b/bzip2.1
index 174b15f..11d97bb 100644
--- a/bzip2.1
+++ b/bzip2.1
@@ -13,6 +13,9 @@
 [
 .I "filenames \&..."
 ]
+.br
+.B bzip2
+.RB [ " \-h|\-\-help " ]
 .ll -8
 .br
 .B bunzip2
@@ -21,12 +24,18 @@
 .I "filenames \&..."
 ]
 .br
+.B bunzip2
+.RB [ " \-h|\-\-help " ]
+.br
 .B bzcat
 .RB [ " \-s " ]
 [
 .I "filenames \&..."
 ]
 .br
+.B bzcat
+.RB [ " \-h|\-\-help " ]
+.br
 .B bzip2recover
 .I "filename"
 
@@ -238,6 +247,9 @@
 Further \-v's increase the verbosity level, spewing out lots of
 information which is primarily of interest for diagnostic purposes.
 .TP
+.B \-h \-\-help
+Print a help message and exit.
+.TP
 .B \-L --license -V --version
 Display the software version, license terms and conditions.
 .TP
diff --git a/manual.xml b/manual.xml
index ea9fca2..7c9e4ec 100644
--- a/manual.xml
+++ b/manual.xml
@@ -160,12 +160,21 @@
  <listitem><para><computeroutput>bzip2</computeroutput> [
   -cdfkqstvzVL123456789 ] [ filenames ...  ]</para></listitem>
 
+ <listitem><para><computeroutput>bzip2</computeroutput> [
+  -h | --help ]</para></listitem>
+
  <listitem><para><computeroutput>bunzip2</computeroutput> [
   -fkvsVL ] [ filenames ...  ]</para></listitem>
 
+ <listitem><para><computeroutput>bunzip2</computeroutput> [
+  -h | --help ]</para></listitem>
+
  <listitem><para><computeroutput>bzcat</computeroutput> [ -s ] [
   filenames ...  ]</para></listitem>
 
+ <listitem><para><computeroutput>bzcat</computeroutput> [
+  -h | --help ]</para></listitem>
+
  <listitem><para><computeroutput>bzip2recover</computeroutput>
   filename</para></listitem>
 
@@ -397,6 +406,10 @@
   will not be suppressed.</para></listitem>
  </varlistentry>
 
+ <varlistentry><term><computeroutput>-h --help</computeroutput></term>
+ <listitem><para>Print a help message and exit.</para></listitem>
+ </varlistentry>
+
  <varlistentry>
  <term><computeroutput>-v --verbose</computeroutput></term>
  <listitem><para>Verbose mode -- show the compression ratio for