issue with $smcFunc['ucwords'] not being loaded

- addresses an issue with the upgrade script where $smcFunc['ucwords'] was not defined for that process
- tested using the SMF 2.1 upgrade an a local installation of SMF 2.0.9
- also edited some grammar within comments in that area of code (let's = let us)

Signed-off-by: -Underdog- github.underdog@gmail.com