Merge pull request #166 from Minalien/master

Added more assets from Media-Source.
Updated unit toughness values so that they more easily integrate into the new toughness changes.
Merge pull request #167 from Minalien/master

Updated combat system to now utilize a percentage-based damage reduction...
Merge pull request #168 from Minalien/master

Fixed implicit casting issue in combat system behavior.
Merge branch 'master' of https://github.com/Tactibru/Game
Merge pull request #169 from DerKrieger/master

Updated Unit Toughness
Merge pull request #170 from Minalien/master

Began implementing unit asset repositories.
Continued work on asset repository system.

Signed-off-by: Ken 'Minalien' Murray <minalien@gmail.com>
Merge branch 'master' of github.com:Tactibru/Game