StringIO compatibility for python3

StringIO can be replaced with six.moves.StringIO which can provide
compatibility for Python 2 and 3. So does cStringIO.

Change-Id: Ieed1e97f1832e56717bc905114eb73fd6c4c4d04
Fix the Alarm documentation of Web API V2

Correct the Alarm example on the API documentation to contain a
valid Alarm sample and complete the Note section with information
about the connection between the type and rules fields of the
Alarm.

Fixes bug #1245362

Change-Id: Id7209d3f7a7ab29a50bdb1dfbe90937b1c7c6c8d
Move enable_acl and debug config to ceilometer.conf

These user editable config params are moved from
pecan config to ceilometer.conf

Change-Id: I8686987e5d92e38e2a9cfbd3f35eea0cc2b443c5
Closes-bug: #1256111
Merge "Move enable_acl and debug config to ceilometer.conf"
Merge "Fix the Alarm documentation of Web API V2"
Merge "StringIO compatibility for python3"