Add throttling when restoring E-Hentai/ExHentai galleries.

app/src/main/java/exh/eh/EHentaiThrottleManager.kt

@@ -0,0 +1,31 @@
+package exh.eh
+
+class EHentaiThrottleManager(private val max: Int = THROTTLE_MAX,
+                             private val inc: Int = THROTTLE_INC) {
+    private var lastThrottleTime: Long = 0
+    var throttleTime: Long = 0
+        private set
+
+    fun throttle() {
+        //Throttle requests if necessary
+        val now = System.currentTimeMillis()
+        val timeDiff = now - lastThrottleTime
+        if(timeDiff < throttleTime)
+            Thread.sleep(throttleTime - timeDiff)
+
+        if(throttleTime < max)
+            throttleTime += inc
+
+        lastThrottleTime = System.currentTimeMillis()
+    }
+
+    fun resetThrottle() {
+        lastThrottleTime = 0
+        throttleTime = 0
+    }
+
+    companion object {
+        const val THROTTLE_MAX = 5500
+        const val THROTTLE_INC = 20
+    }
+}