small doc page changes, format and content on doc page tarballs

doc/src/Build_basics.txt

@@ -292,6 +292,10 @@ This will create a lammps/doc/html dir with the HTML doc pages so that
 you can browse them locally on your system.  Type "make" from the
 lammps/doc dir to see other options.
 
+NOTE: You can also download a tarball of the documention for the
+current LAMMPS version (HTML and PDF files), from the website
+"download page"_http://lammps.sandia.gov/download.html.
+
 :line
 
 Install LAMMPS after a build :h4,link(install)

doc/src/Howto_client_server.txt

@@ -7,7 +7,7 @@ Documentation"_ld - "LAMMPS Commands"_lc :c
 
 :line
 
-Using LAMMPS in client/server mode
+Using LAMMPS in client/server mode :h3
 
 Client/server coupling of two codes is where one code is the "client"
 and sends request messages to a "server" code.  The server responds to

doc/src/Install_tarball.txt

@@ -7,7 +7,7 @@ Documentation"_ld - "LAMMPS Commands"_lc :c
 
 :line
 
-Download source as a tarball :h3
+Download source and documentation as a tarball :h3
 
 You can download a current LAMMPS tarball from the "download page"_download
 of the "LAMMPS website"_lws.
@@ -22,6 +22,10 @@ few times per year, and undergo more testing before release.  Patch
 releases occur a couple times per month.  The new contents in all
 releases are listed on the "bug and feature page"_bug of the website.
 
+Both tarballs include LAMMPS documentation (HTML and PDF files)
+corresponding to that version.  The download page also has an option
+to download the current-version LAMMPS documentation by itself.
+
 Older versions of LAMMPS can also be downloaded from "this
 page"_older.
 

doc/src/Packages_details.txt

@@ -46,6 +46,7 @@ as contained in the file name.
 "MANYBODY"_#PKG-MANYBODY,
 "MC"_#PKG-MC,
 "MEAM"_#PKG-MEAM,
+"MESSAGE"_#PKG-MESSAGE,
 "MISC"_#PKG-MISC,
 "MOLECULE"_#PKG-MOLECULE,
 "MPIIO"_#PKG-MPIIO,