fixes erroneous ref to l3_agent.py

As noted in the bug report, previously this paragraph referred to a
flag that didn't exist in a python file that didn't contain it.

Flag name fixed, file name fixed.

fixes bug 1174195

Change-Id: I41118cc426ff39a42d41b26d915f9ed75fbbe3bd
Typo/grammar fixes on block storage guide

Fixes a range of typos and grammatical errors in the block storage
 guide

fixes bug 1172541

Change-Id: I7961c29fd55118105f61ca35e16c5f678dc15537
Merge "Typo/grammar fixes on block storage guide"
Typo/grammar fixes for compute admin manual

Various typo/grammar fixes for the compute admin manual

fixes bug 1172501

Change-Id: Ic37bc4ac74ba8969a0d83a1153bb001507eaa5d4