samoura unts...to debump

[ptizoom]

due to their appearance too early in tech tree and without much historical context and because
they just break the game too early (as it happened in LT-AU1), I think judicious to change the parameters of these units:

from...
* HP15 to HP10 or so...
* D4 to D2....
* A5 to A4...
* MP2 to 1

but maybe, and after all, samurai are fast units by nature, there is a case to increase their firepower instead ?