Merge branch 'FixCUnitTests' into 'master'

[CA-187325] Fix C unit tests runner

The unit tests for C started failing as a consequence of a change in the xapiobject code.

I've:

1. Fixed the CSDK code
2. Tweaked the name of a property. I checked for other uses and couldn't find any so it should be safe enough
3. Took the opportunity to tidy up some annoying whitespace flake8 was complaining about at the time

Tested using 1221414

Check for other instances of the rename:
```
chrishard@dhcp-5-87 ~/xenrt [FixCUnitTests] $ ack isLocal
exec/testcases/xenserver/gui.py
541:        localSrName = next(sr for sr in self._host.xapiObject.localSRs if sr.isLocalStorage).name

exec/xenrt/lib/xenserver/objects.py
268:    def isLocalStorage(self):
```

See merge request !120

diff --cc exec/testcases/xenserver/gui.py
Simple merge