grep: extend functionality, add man page entry, add unit test.
walkchangerevs now returns a two-tuple. Its behaviour is also
extensively commented.
The annotate command's getname function has been factored out to a new
function, trimname, so it can be shared between annotate and grep.
The behaviour of grep has been beefed up, so that it now performs a
number of useful functions.
1:f4d7a8c73d23
0:232e179b3f29
f4d7a8c73d23 tip
232e179b3f29
232e179b3f29+
232e179b3f29
f4d7a8c73d23 tip
merge: warning: conflicts during merge
merging file1
merging file1 failed!
diff -r f4d7a8c73d23 file1
--- a/file1
+++ b/file1
@@ -1,3 +1,7 @@
added file1
another line of text
+<<<<<<<
+changed file1 different
+=======
changed file1
+>>>>>>>
M file1
f4d7a8c73d23+ tip
f4d7a8c73d23 tip
f4d7a8c73d23 tip
f4d7a8c73d23 tip