Fixes broken doc references

The references in configuringservices.rst did not resolve to
html addresses and were not referenced correctly in the browser.
This new fix will use the preferred way to cross reference documents.
Has the disadvantage that if the reference changes, it need to be
updated at severeal places in the document.

Change-Id: I3b8f71a95e66266b569aa1141985e47f1f4554c3
Closes-Bug: 1232878
remove the nova dependency in the ec2_token middleware

Change-Id: I34812522b55e38d3ea030638bbae75d65f507c90
Closes-Bug: #1178740
Use abstract base class for catalog driver

Use the abc module for managing abstract base classes in the driver
layer and add missing methods to concrete classes.

bp abstract-base-class-drivers

Change-Id: If66b9bd3ebcfc3a59151b52a46407a36d2a9352b
Adds more uniformity to identity update_user calls

 * It was not possible to change a user's name using the KVS driver.
 * The KVS driver was not filtering the user dict before handing it
   back to that caller.
 * Adds a test to the LDAP driver to explicitly show that changing a
   user's name is not allowed.

Related-Bug: #1214686
Change-Id: Ia0951a58ef09833849d3eb5e714c7efbd901f5c5
Merge "Use abstract base class for catalog driver"
Merge "Adds more uniformity to identity update_user calls"
Merge "Fixes broken doc references"
Merge "remove the nova dependency in the ec2_token middleware"