Replaced references to Firefox with Mozilla

So, I'm still not really sure how I managed to raise conflicts in my prior attempts. Pretty embarrassing! I started over with a new branch, and I pulled the original repository (using the mainline convention).  I then pulled my gh-15 branch with rebase. I didn't see any mention of conflicts, nor can I find any of the arrow groups signifying a conflict. 

At this point, I'm just going to have to break down everything that I'm doing on a step-by-step basis if this still has conflicts. Sorry about making something as simple as this such a hassle.

Thanks for your help!