Merge lp://staging/~kyrofa/unity-scopes-api/1452423_fix-tutorial-typos into lp://staging/unity-scopes-api

Fix a couple typos in the tutorial.

This simply fixes a couple of typos found in the tutorial.

To test:

1) Look at old documentation, and notice the following sentence: "Prior to sending any queries, the scopes run time calls run() if your stop() method completed successfully (did not throw an exception)."

2) Regenerate documentation based on this MP:

$ cmake /path/to/src
$ make doc

3) Open up doc/index.html and notice that the sentence is now: "Prior to sending any queries, the scopes run time calls run() if your start() method completed successfully (did not throw an exception)." A few other smaller typos were also corrected.