Easier discovery of modern cavalry for westernized tags

[rogerburks]

The 2% discovery rate for hussars (especially) seems draconian, especially considering that it is possible to discover tanks and airplanes before discovering modern cavalry. This fix addresses that by making the discovery rate 100% for westernized tags. This seems appropriate since hussars may have historical origins as early as the late 14th century.

The operative part of the code to fix is here, adding a 98 modifier for westernized tags:

ccHFM/ccHFM/inventions/army_inventions.txt

Lines 1202 to 1214 in e9e6e9b

	hussar_activation = {
	limit = { military_staff_system = 1 }
	chance = {
	base = 2
	modifier = {
	factor = -2
	not = { civilized = yes }
	}
	}
	effect = {
	activate_unit = hussar
	}
	}

Optionally, a there could be added a non-zero chance for non-westernized tags to discover them under certain reforms, but I have not added this.

[moretrim]

Pending on #112.