[PATCH] archimport documentation update

Updated and expanded the command description, and added a reference of the
command line options.

Signed-off-by: Martin Langhoff <martin@catalyst.net.nz>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/git-archimport.txt

@@ -8,24 +8,63 @@ git-archimport - Import an arch repository into git
 
 SYNOPSIS
 --------
-`git-archimport` [--option...] <args>
+`git-archimport` [ -h ] [ -v ] [ -T ] [ -t tempdir ] 
+                 <archive/branch> [ <archive/branch> ]
 
 DESCRIPTION
 -----------
-The script expects you to provide the key roots where it can start the
-import from an 'initial import' or 'tag' type of Arch commit. It will
-then follow all the branching and tagging within the provided roots.
+Imports a project from one or more Arch repositories. It will follow branches
+and repositories within the namespaces defined by the <archive/branch>
+parameters suppplied. If it cannot find the remote branch a merge comes from
+it will just import it as a regular merge. If it can find it, it will perform
+a merge whenever possible. 
 
-It will die if it sees branches that have different roots.
+The script expects you to provide the key roots where it can start the import 
+from an 'initial import' or 'tag' type of Arch commit. It will follow and import 
+new branches within the provided roots. 
 
+It expects to be dealing with one project only. If it sees 
+branches that have different roots, it will refuse to run. In that case, edit your
+<archive/branch> parameters to define clearly the scope of the import. 
+
+`git-archimport` uses `tla` extensively in the background to access the Arch repository.
+Make sure you have a recent version of `tla` available in the path. `tla` must
+know about the repositories you pass to `git-archimport`. 
+
+For the initial import `git-archimport` expects to find itself in an empty 
+directory. To follow the development of a project that uses Arch, rerun 
+`git-archimport` with the same parameters as the initial import to perform incremental imports.
+of a project using Arch.
+
+Patch merge data from Arch is used to mark merges in GIT as well. GIT 
+does not care much about tracking patches, and only considers a merge when a
+branch incorporates all the commits since the point they forked. The end result
+is that GIT will have a good idea of how far branches have diverged. So the 
+import process does lose some patch-trading metadata.
+
+Fortunately, when you try and merge branches imported from Arch, 
+GIT will find a good merge base, and it has a good chance of identifying 
+patches that have been traded out-of-sequence between the branches. 
 
 OPTIONS
 -------
---option::
-	Some option not yet documented.
 
-<args>...::
-	Some argument not yet documented.
+-h::
+	Display usage.
+
+-v::
+	Verbose output. 
+
+-T::
+	Many tags. Will create a tag for every commit, reflecting the commit 
+	name in the Arch repository.
+
+-t <tmpdir>::
+	Override the default tempdir.
+
+
+<archive/branch>::
+	Archive/branch identifier in a format that `tla log` understands. 
 
 
 Author
@@ -34,7 +73,7 @@ Written by Martin Langhoff <martin@catalyst.net.nz>.
 
 Documentation
 --------------
-Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
+Documentation by Junio C Hamano, Martin Langhoff and the git-list <git@vger.kernel.org>.
 
 GIT
 ---