Adds explanatory text to warn admins when creating aggreates

to avoid confusing users booting in different availabilty zones.

Change-Id: I55550794c399c25f344a82bea7ea7661ad025228
Closes-bug: 1222665
Merge "Adds explanatory text to warn admins when creating aggreates"
Ensures cinder quotas are documented, just had to add to one table.

Double-checked dashboard and CLI instructions.

Change-Id: I8391582787a0cdb62e55380b3efb680c6d98f4fb
Closes-bug: 1188472