Implement database feature

A simple JSON-based database that works through loading full self-copy
into the memory. Should be more than enough for the needs of kf modding.

fixtures/database/administration/registered.json

@@ -0,0 +1,13 @@
+{
+    "76561198025127722": {
+        "allowed_ips": ["127.0.0.1", "192.168.0.100"],
+        "groups": ["admin"],
+        "ip_lock": true,
+        "password_hash": "fce798e0804dfb217f929bdba26745024f37f6b6ba7406f3775176e20dd5089d"
+    },
+    "76561198044316328": {
+        "groups": ["admin"],
+        "ip_lock": false,
+        "password_hash": "fce798e0804dfb217f929bdba26745024f37f6b6ba7406f3775176e20dd5089d"
+    }
+} 

fixtures/database/game/general.json

@@ -0,0 +1,12 @@
+{
+    "76561198025127722": {
+        "walked": 1073,
+        "dosh_thrown": 483482,
+        "achievements": ["kf:LabCleaner", "kf:ChickenFarmer", "scrn:playedscrn"]
+    },
+    "76561198044316328": {
+        "walked": 1693,
+        "dosh_thrown": 527624,
+        "achievements": ["kf:PubCrawl", "kf:FascistDietitian", "kf:GimliThatAxe!", "scrn:playedscrn"]
+    }
+}

fixtures/database/game/perks.json

@@ -0,0 +1,12 @@
+{
+    "76561198025127722": {
+        "headshots": 582,
+        "assault_rifle_damage": 9067,
+        "stalker_kills": 143
+    },
+    "76561198044316328": {
+        "explosive_damage": 19674,
+        "shotgun_damage": 3835,
+        "welded_amount": 1
+    }
+}