Revert "Revert "Update 2014-09-17-se-software-engineering-background.md""

This reverts commit 2e8ad484d9f216fd9ccf4ecc20ffbb80856102d4.
Revert "Revert "Revert "Update 2014-09-17-se-software-engineering-background.md"""

This reverts commit f90fd334d71f2b5f98def19a5acaaf7c9bc7bf94.