gui: improve memory usage (#79)

- don't use suffix tree in search
- decrease default working threads count (only 1 for background jobs)
- use string refs for store only one code string without duplicates
- use cache for creating UI nodes
- allow to disable autostart for background jobs (decompilation and index)

jadx-cli/src/main/java/jadx/cli/JadxCLIArgs.java

@@ -29,7 +29,7 @@ public class JadxCLIArgs implements IJadxArgs {
 	protected String outDirName;
 
 	@Parameter(names = {"-j", "--threads-count"}, description = "processing threads count")
-	protected int threadsCount = Runtime.getRuntime().availableProcessors();
+	protected int threadsCount = Math.max(1, Runtime.getRuntime().availableProcessors() / 2);
 
 	@Parameter(names = {"-f", "--fallback"}, description = "make simple dump (using goto instead of 'if', 'for', etc)")
 	protected boolean fallbackMode = false;

jadx-cli/src/main/resources/logback.xml

@@ -5,7 +5,7 @@
             <level>INFO</level>
         </filter>
         <encoder>
-            <pattern>%-5level - %msg%n</pattern>
+            <pattern>%d{HH:mm:ss} %-5level - %msg%n</pattern>
         </encoder>
     </appender>