global_author does not update when rebuild action is triggered

[jakimfett]

Title says it all.

To reproduce:

1. checkout a fresh copy of bb.sh
2. execute ./bb.sh post
3. publish the post
4. edit .config to set global_author (leaving the first line empty as specified in global_title in .config ignored #183)
5. create a new post with ./bb.sh post, observing that the author is correctly set
6. execute ./bb.sh rebuild and see that the author in the first post remains the same 'John Smith' value

--
To remediate:

1. remove the HTML file associated with the post
2. edit the markdown file associated with the post with ./bb.sh post <the-file-name>.md
3. (re)publish the post by selecting "p" after saving and exiting your chosen editor

[jakimfett]

Addendum:
Removing the post HTML file seems to duplicate the markdown file and add a second footer. Rebuilding seems to fix the latter but not the former.

Sometimes, the global_email doesn't update when rebuild action is triggered, either.
I'm continuing to test to see if there are other variables that aren't updated on rebuild, either.