DataCache and changes for game update

Recent game update changed pokememes view in pokedeks, so we need to
reflect it by updating parser.

Introducing DataCache - a silver bullet for eliminating lags linked to
database queries. Less queries, more in RAM, faster work. Needs testing
in production environment.

lib/datacache/locations.go

@@ -0,0 +1,45 @@
+// i2_bot – Instinct PokememBro Bot
+// Copyright (c) 2018 Vladimir "fat0troll" Hodakov
+
+package datacache
+
+import (
+	"errors"
+	"git.wtfteam.pro/fat0troll/i2_bot/lib/dbmapping"
+	"strconv"
+)
+
+func (dc *DataCache) initLocations() {
+	c.Log.Info("Initializing Locations storage...")
+	dc.locations = make(map[int]*dbmapping.Location)
+}
+
+func (dc *DataCache) loadLocations() {
+	c.Log.Info("Load current Locations data from database to DataCache...")
+	locations := []dbmapping.Location{}
+	err := c.Db.Select(&locations, "SELECT * FROM locations")
+	if err != nil {
+		// This is critical error and we need to stop immediately!
+		c.Log.Fatal(err.Error())
+	}
+
+	dc.locationsMutex.Lock()
+	for i := range locations {
+		dc.locations[locations[i].ID] = &locations[i]
+	}
+	c.Log.Info("Loaded locations in DataCache: " + strconv.Itoa(len(dc.locations)))
+	dc.locationsMutex.Unlock()
+}
+
+func (dc *DataCache) findLocationIDByName(name string) (int, error) {
+	dc.locationsMutex.Lock()
+	for i := range dc.locations {
+		if dc.locations[i].Name == name {
+			dc.locationsMutex.Unlock()
+			return i, nil
+		}
+	}
+
+	dc.locationsMutex.Unlock()
+	return 0, errors.New("There is no location with name = " + name)
+}