cache manager and clearing tracing cache (#1769)

* removed configure_cache method

* generic cache_manager struct

* fixed #1743, tracing caches are cleared

* removed deadlocks in garbage_collect, implemented HeapSizeOf for traces

* trace cache config

* fixed carbage typo

ethcore/src/client/client.rs

@@ -549,6 +549,7 @@ impl Client {
 	pub fn tick(&self) {
 		self.chain.collect_garbage();
 		self.block_queue.collect_garbage();
+		self.tracedb.collect_garbage();
 
 		match self.mode {
 			Mode::Dark(timeout) => {
@@ -582,11 +583,6 @@ impl Client {
 		}
 	}
 
-	/// Set up the cache behaviour.
-	pub fn configure_cache(&self, pref_cache_size: usize, max_cache_size: usize) {
-		self.chain.configure_cache(pref_cache_size, max_cache_size);
-	}
-
 	/// Look up the block number for the given block ID.
 	pub fn block_number(&self, id: BlockID) -> Option<BlockNumber> {
 		match id {