Samurai Update

Lowered the combat strength from 37 to 28.  The Longswordsman combat
strength is 24 (for reference).
Typo correction

The Wealth Finisher stated "Smithy"
Changed to "Smith" since that term isn't used anymore.
Spelling corrections

Changed "recieve" to "receive" in a few places.  Sorry I'm a
perfectionist for spelling and grammar...
Archery prereq for The Wheel tech

Added Archery as a prereq for the Wheel.  It makes zero sense that you
can build Chariot Archers without having Archery or the Archer unit
first.
Removed Tech Prereq

Since Archery is a prereq for the Wheel, and the Wheel is a prereq for
Mathematics, there doesn't need to be a useless link for Archery to
Mathematics.
Merge pull request #184 from EricB1/new-features

Seems reasonable to me.