Performance improvements (#746)

* Misc minor performance improvements

* Use more concise loop syntax

* Use more concise Collection sort syntax

* Use StringUtils pad methods

* Optimize some loops and double-map-lookups

* Optimize array instantiation

There are two styles to convert a collection to an array: either
using a pre-sized array (like c.toArray(new String[c.size()])) or
using an empty array (like c.toArray(new String[0]).

In older Java versions using pre-sized array was recommended,
as the reflection call which is necessary to create an array
of proper size was quite slow. However since late updates of
OpenJDK 6 this call was intrinsified, making the performance
of the empty array version the same and sometimes even better,
compared to the pre-sized version. Also passing pre-sized array
is dangerous for a concurrent or synchronized collection as
a data race is possible between the size and toArray call
which may result in extra nulls at the end of the array,
if the collection was concurrently shrunk during the operation.

* Cleanup string concatenation

* Use EnumMap where possible

* Use FastMath instead of Math

* Initialize complex things only once

* Reduce method size to aloow more JIT inlining

* remove map of short->float

* Move field to local variable

* Cleanup Map lookup

Co-authored-by: Rob Ekl <xwq876@zebra.com>

src/main/java/io/github/dsheirer/channel/metadata/ChannelMetadataPanel.java

@@ -55,6 +55,7 @@ import java.awt.Component;
 import java.awt.event.MouseAdapter;
 import java.awt.event.MouseEvent;
 import java.text.DecimalFormat;
+import java.util.EnumMap;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -68,8 +69,8 @@ public class ChannelMetadataPanel extends JPanel implements ListSelectionListene
     private UserPreferences mUserPreferences;
     private JTable mTable;
     private Broadcaster<ProcessingChain> mSelectedProcessingChainBroadcaster = new Broadcaster<>();
-    private Map<State,Color> mBackgroundColors = new HashMap<>();
-    private Map<State,Color> mForegroundColors = new HashMap<>();
+    private Map<State,Color> mBackgroundColors = new EnumMap<>(State.class);
+    private Map<State,Color> mForegroundColors = new EnumMap<>(State.class);
     private JTableColumnWidthMonitor mTableColumnMonitor;
 
     /**