Document cirros password in install guide

Describe how to ssh to cirros using password.

Backport: havana

Change-Id: Ie45c2d343ef2b6bc560d59a67224aa79ccf48e87
(cherry picked from commit c1e2121099c26d686b7b7b0b27499fb1338a439c)
Install Guide: Properly mark instructions for Ubuntu

The openstack-config command line missed the profiling for everything
not Ubuntu/Debian. The instructions for Ubuntu/Debian are properly
marked.

Change-Id: Ia1c87814079793cce2a141e125fc4cf97840790a
backport: havana
Closes-Bug: #1244278
(cherry picked from commit adc16bcd26c32ddf8b0df3f7f67b267164a050a5)
Install Guide: Edits on heat installation

General edits

Change-Id: I7a514ed2575aed0be06262a8429220175ee64eb1
backport: havana
(cherry picked from commit c110a8454bb5c6c8f348c5c311fcd30cfd319f4d)
Merge "Document cirros password in install guide" into stable/havana
Merge "Install Guide: Properly mark instructions for Ubuntu" into stable/havana
Merge "Install Guide: Edits on heat installation" into stable/havana