Added Navigation tech with Seaport building and Frigate unit

Water maps are out of beta and are now default!

android/assets/jsons/Buildings.json

@@ -192,7 +192,8 @@
 		specialistSlots:{gold:1},
 		hurryCostModifier:25,
 		percentStatBonus:{gold:25},
-		uniques:["Provides 1 extra copy of each improved luxury resource near this City","+2 Gold for each source of Oil and oasis"],
+		uniques:["Provides 1 extra copy of each improved luxury resource near this City",
+			"+2 Gold for each source of Oil and oasis"],
 		requiredTech:"Currency"
 	},
 	{
@@ -417,6 +418,14 @@
 		uniques:["Free Great Artist Appears"],
 		requiredTech:"Archaeology"
 	},
+	{
+		name:"Seaport",
+		hurryCostModifier:25,
+		maintenance:2,
+		uniques:["+1 production and gold from all sea resources worked by the city",
+			"Can only be built in coastal cities", "+15% production of naval units"]
+		requiredTech:"Navigation"
+	},
 	{
 		name:"Taj Mahal",
 		culture:1,

android/assets/jsons/Techs.json

@@ -222,7 +222,7 @@
 				name:"Astronomy",
 				row:2,
 				baseDescription:"Increases embarked movement +1",
-				prerequisites:[/*"Compass",*/"Education"]
+				prerequisites:["Compass","Education"]
 			},
 			{
 				name:"Acoustics",
@@ -253,12 +253,11 @@
 		buildingCost:300,
 		wonderCost:750,
 		techs:[
-			/*{
+			{
 				name:"Navigation",
 				row:2,
-				prerequisites:["Astronomy"],
-				baseDescription:"Does nothing since we have no sea tiles - In theory, allows construction of Frigates and Seaports"
-			},*/
+				prerequisites:["Astronomy"]
+			},
 			{
 				name:"Architecture",
 				row:4,
@@ -291,7 +290,7 @@
 			{
 				name:"Archaeology",
 				row:2,
-				prerequisites:["Astronomy"]
+				prerequisites:["Navigation"]
 			},
 			{
 				name:"Scientific Theory",

android/assets/jsons/Units.json

@@ -245,6 +245,8 @@
 		rangedStrength:17
 		cost: 100,
 		requiredTech:"Compass",
+		obsoleteTech:"Navigation",
+		upgradesTo:"Frigate",
 		uniques:["Cannot enter ocean tiles"]
 		hurryCostModifier:20
 	},
@@ -304,6 +306,17 @@
 		requiredTech:"Gunpowder",
 		hurryCostModifier:20
 	},
+	{
+		name:"Frigate",
+		unitType:"WaterRanged",
+		movement:5,
+		strength:25,
+		rangedStrength:28,
+		cost: 185,
+		requiredResource:"Iron",
+		requiredTech:"Navigation",
+		hurryCostModifier:20
+	},
 	{
 		name:"Lancer",
 		unitType:"Mounted",