Updated Mac date, proposed clearer wording

When using these instructions to install on Mac, I found a specific sentence confusing. I have added the following changes:

1. After verifying the installation instructions on Mac, I have changed the 'last verified date' for Mac (in MMM DD, YYYY to avoid ambiguity).

2. I found a sentence under 'Set up the database' to be very confusing, and am proposing the following wording:

old: This will print out *lots* of text, when you are done you should see something like the output listed in Output Samples below, at the end of which, your tables should be ready. You're ready to run the site.

new: This will print out *lots* of text. Once all of the text is printed, you should see something like the output listed in `Output Samples`_ below. Afterwards, your tables should be ready. You're ready to run the site.

3. I think having a link to the section 'Output Samples' would be useful, as this was not immediately clear to me.
Merge pull request #267 from younjin/patch-3

Updated Mac date, proposed clearer wording.