Fix typo in comment

This is a trivial change, fixing a spelling mistake in a comment.

Change-Id: I124faf67bc2b3596a2ecf88c66c57f3abb362fd9
VMware: use default values in get_info() when properties are missing

The properties that we retrieve from VirtualMachineConfigSummary are
optional ('summary.config.numCpu', 'summary.config.memorySizeMB') and
if they are missing we should return default values from get_info()

This patch also improves the unit test for get_info(). It removes the
test in test_driver_api.py (test_get_info() and test_spawn() are the
same) and adds a new test in test_vmops.py

Closes-Bug: 1317912
Change-Id: Ibbb28985d13de371fdac8a119ad820d25acc21be
Add a reference to the nova developer documentation

I've showed these docs to more people than I care to. It would be
extremely helpful to reference them in HACKING, which is generally
the first thing people read if they intend to hack.

Change-Id: I9194d98f5525e29711b4a1b26414a50b8ceba525
Merge "VMware: use default values in get_info() when properties are missing"
Merge "Fix typo in comment"
Merge "Add a reference to the nova developer documentation"