patman: Allow linking a series with patchwork

Add a new Series-links tag to tell patman how to find the series in
patchwork. Each item is the series ID optionally preceded by the series
version that the link refers to. An empty version indicates this is the
latest series.

For example:

   Series-links: 209816 1:203302

Documentation is added in a later patch.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/patman/README

@@ -187,6 +187,21 @@ Series-name: name
 	patman does not yet use it, but it is convenient to put the branch
 	name here to help you keep track of multiple upstreaming efforts.
 
+Series-links: [id | version:id]...
+	Set the ID of the series in patchwork. You can set this after you send
+	out the series and look in patchwork for the resulting series. The
+	URL you want is the one for the series itself, not any particular patch.
+	E.g. for http://patchwork.ozlabs.org/project/uboot/list/?series=187331
+	the series ID is 187331. This property can have a list of series IDs,
+	one for each version of the series, e.g.
+
+	   Series-links: 1:187331 2:188434 189372
+
+	Patman always uses the one without a version, since it assumes this is
+	the latest one. When this tag is provided, patman can compare your local
+	branch against patchwork to see what new reviews your series has
+	collected ('patman status').
+
 Cover-letter:
 This is the patch set title
 blah blah

tools/patman/func_test.py

@@ -417,6 +417,7 @@ Series for my board
 This series implements support
 for my glorious board.
 END
+Series-links: 183237
 ''', 'serial.c', '''The code for the
 serial driver is here''')
         self.make_commit_with_file('bootm: Make it boot', '''

tools/patman/series.py

@@ -16,7 +16,7 @@ from patman import tools
 
 # Series-xxx tags that we understand
 valid_series = ['to', 'cc', 'version', 'changes', 'prefix', 'notes', 'name',
-                'cover_cc', 'process_log']
+                'cover_cc', 'process_log', 'links']
 
 class Series(dict):
     """Holds information about a patch series, including all tags.