Some changes in charts api, to make charts scale more adequate. Add lines inserted/deleted stats to activity chart.

diff --git a/pygit/chart.py b/pygit/chart.py
index 167a74a..9b51665 100644
--- a/pygit/chart.py
+++ b/pygit/chart.py
@@ -16,9 +16,11 @@ class Place(object):
     self.y0 = y0
     self.width = width
     self.height = height
-    self.x_ticks = None
+    self.scale_set = False

   def set_scale(self,x_ticks,y_max):
+    if self.scale_set:
+      return
     self.x_ticks = x_ticks
     self.y_max = y_max
     self.step_x = float(self.width)/x_ticks
@@ -50,6 +52,11 @@ class Chart(object):
       place = Place(self.cx,pl,height-place_height*i-py, width-pl-pr, place_height-2*py)
       self.places.append(place)

+  def set_scale(self,place,ticks_x,max_y):
+    self.places[place].set_scale(ticks_x,max_y)
+    self.places[place].scale_set = True
+
+
   def draw(self,lst,color=(0.9,0.2,0.2),place=0):
     pc = self.places[place]
     pc.set_scale(len(lst)-1,max(lst))
diff --git a/pygit/pygit.py b/pygit/pygit.py
index 99fc512..38a5674 100644
--- a/pygit/pygit.py
+++ b/pygit/pygit.py
@@ -129,11 +129,13 @@ def group_by_date(lst):

 def stats_sum(lst):
   "[Commit] -> dict(lines=?, files=?)"
-  r = {'lines': 0, 'files': 0}
+  r = {'lines': 0, 'files': 0,'insertions':0, 'deletions':0}
   for cm in lst:
     try:
       r['lines'] += cm.stats.total['lines']
       r['files'] += cm.stats.total['files']
+      r['insertions'] += cm.stats.total['insertions']
+      r['deletions'] += cm.stats.total['deletions']
     except ValueError:
       pass
   return r
@@ -148,7 +150,9 @@ def commits_stats(rid,branch='master'):
   stats = [stats_sum(g[1]) for g in grp]
   files = [s['files'] for s in stats]
   lines = [s['lines'] for s in stats]
-  return dates,n_commits,files,lines
+  inss  = [s['insertions'] for s in stats]
+  dels  = [s['deletions'] for s in stats]
+  return dates,n_commits,files,lines,inss,dels

 def commit_stats(rid,cid):
   r = open_repo(rid)
diff --git a/pygit/views.py b/pygit/views.py
index 0c2dfa5..c127c36 100644
--- a/pygit/views.py
+++ b/pygit/views.py
@@ -34,11 +34,15 @@ def one_repo(request,rid,branch='master'):
   tags = pygit.tags(rid)
   cs  = pygit.commits(rid,branch)
   dirs,files = pygit.root_tree(rid,branch)
-  dates,n_commits,files_s,lines = pygit.commits_stats(rid,branch)
+  dates,n_commits,files_s,lines,inss,dels = pygit.commits_stats(rid,branch)
   cht = Chart(900,200,n=2)
+#   cht.set_scale(0,len(n_commits)-1,max(max(n_commits),max(files_s)))
+  cht.set_scale(1,len(inss)-1,max(inss))
   cht.draw(n_commits,place=0,color=(0.9,0.9,0.2))
-  cht.draw(files_s,place=1,color=(0.2,0.2,0.9))
-  cht.draw(lines,place=1,color=(0.2,0.9,0.2))
+  cht.draw(files_s,place=0,color=(0.3,0.3,0.3))
+  cht.draw(inss,place=1,color=(0.2,0.2,0.9))
+  cht.draw(dels,place=1,color=(0.9,0.2,0.2))
+#   cht.draw(lines,place=1,color=(0.2,0.9,0.2))
   cht.labels(dates)
   chart = cht.finish()
   return render_it('repo.html',