Add functionality to batch the meetings list

Created and export, to jinja2, a batch_meetings fuction that will pivot
the sorted list of meetings into a number of colums.  This can be used
in a jinja template like:

  {% for column in batch_meetings(meetings, 4)|batch(4) %}

So the list:
     [A, B, C, D, E, F , G, H]

Dsisplays as:
    A C E G
    B D F H

Rather than:
    A B C D
    E F G H

Change-Id: I9d7c6ad9c14a9d6ec3d402a67b73fafae575d369

yaml2ical/index.py

@@ -10,6 +10,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+from __future__ import division
+
 import datetime
 import jinja2
 import logging
@@ -17,6 +19,20 @@ import os
 import os.path
 
 
+def batch_meetings(meetings, batch_size):
+    col_length = len(meetings) // batch_size
+    new_meetings = [None] * len(meetings)
+    src = 0
+
+    for row in range(batch_size):
+        for col in range(col_length):
+            dest = col * batch_size + row
+            new_meetings[dest] = meetings[src]
+            src += 1
+
+    return new_meetings
+
+
 def convert_meetings_to_index(meetings, template, output_file):
     """Creates index file from list of meetings.
 
@@ -30,6 +46,7 @@ def convert_meetings_to_index(meetings, template, output_file):
     loader = jinja2.FileSystemLoader(template_dir)
     env = jinja2.environment.Environment(trim_blocks=True, loader=loader)
     template = env.get_template(template_file)
+    template.globals['batch_meetings'] = batch_meetings
 
     with open(output_file, "w") as out:
         out.write(template.render(meetings=meetings,

yaml2ical/meeting.py

@@ -176,6 +176,7 @@ def load_meetings(yaml_source):
         raise ValueError("No .yaml file, directory containing .yaml files, "
                          "or YAML data found.")
     else:
+        meetings.sort(key=lambda x: x.project)
         return meetings