Install Guide: Merge two steps in Neutron Install

Steps 6 and 8 were referencing the same files while step 7
used another one. Let's merge the steps as proposed in the bug.

Change-Id: I8d379055db86f83bee181632aa84cec891cb9880
backport: havana
Closes-Bug: 1245914
(cherry picked from commit ff12c80be4c553ead48de17189b15b3c5af00c68)
Install Guide: Make titles consistent

We have mixed styles in the guide with regards to capitalization
and do not use gerunds (_ING_ verbs). This fixes the remaining
pieces.

Change-Id: I20a45b77de267a946b8f5b24c4a54fb9461274d0
backport: havana
(cherry picked from commit 87300f8c1efa80c1260f574fbd4190f666472ca5)
Removed instructions to copy .conf files

Bug 1247323 states a requirement to remove the
instructions to copy .conf files between the controller and compute
nodes. Bug 1245968 mentions this as a possible cause of the issue.
This patch progresses both bugs, but resolves neither. Also fixes for
some minor layout and wording issues.

Change-Id: Ia92fbaf9152df561aa38dac4c91e9f38bd425964
backport: havana
Partial-Bug: #1247323
Partial-Bug: #1245968
(cherry picked from commit 7d39198c1f5dd05af6d4b368c78f4fee3532a99d)
Merge "Install Guide: Merge two steps in Neutron Install" into stable/havana
Merge "Install Guide: Make titles consistent" into stable/havana
Merge "Removed instructions to copy .conf files" into stable/havana