Parse git's diff stat summary more flexibly.

Git versions with commit 7f814632f5d4d7af9f4225ece6039dbc44e03079 print the
stat summary output slightly different. There were two changes that affect
GitStats:

a) Singular forms of files/insertions/deletions may be used
b) The number of counts is now variable ranging from 1 to 3:
   1: only files changed if file count is 0
   2: if either insertions or deletions are 0 (not if both are)
   3: where files,insertions and deletions are >0
          or both insertions and deletions are  0

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>

gitstats

 def getkeyssortedbyvaluekey(d, key):
 	return map(lambda el : el[1], sorted(map(lambda el : (d[el][key], el), d.keys())))
 
+def getstatsummarycounts(line):
+	numbers = re.findall('\d+', line)
+	if   len(numbers) == 1:
+		# neither insertions nor deletions: may probably only happen for "0 files changed"
+		numbers.append(0);
+		numbers.append(0);
+	elif len(numbers) == 2 and line.find('(+)') != -1:
+		numbers.append(0);    # only insertions were printed on line
+	elif len(numbers) == 2 and line.find('(-)') != -1:
+		numbers.insert(1, 0); # only deletions were printed on line
+	return numbers
+
 VERSION = 0
 def getversion():
 	global VERSION
 				continue
 
 			# <stamp> <author>
-			if line.find('files changed,') == -1:
+			if re.search('files? changed', line) == None:
 				pos = line.find(' ')
 				if pos != -1:
 					try:
 				else:
 					print 'Warning: unexpected line "%s"' % line
 			else:
-				numbers = re.findall('\d+', line)
+				numbers = getstatsummarycounts(line)
+
 				if len(numbers) == 3:
 					(files, inserted, deleted) = map(lambda el : int(el), numbers)
 					total_lines += inserted
 				continue
 
 			# <stamp> <author>
-			if line.find('files changed,') == -1:
+			if re.search('files? changed', line) == None:
 				pos = line.find(' ')
 				if pos != -1:
 					try:
 				else:
 					print 'Warning: unexpected line "%s"' % line
 			else:
-				numbers = re.findall('\d+', line)
+				numbers = getstatsummarycounts(line);
+
 				if len(numbers) == 3:
 					(files, inserted, deleted) = map(lambda el : int(el), numbers)
 				else: