Respect log level unless the -gvh_log_debug flag is present.

Logger will now only log all messages if the -gvh_log_debug command
line flag is specified. Without the command line flag debug logging
needs to be enabled in each component individually.

Fixes #340

Change-Id: I0b1f38a3e438bd287aa7f906fc8d278df7321b94

Author: Stewart Miles

source/VersionHandlerImpl/src/Logger.cs

@@ -44,6 +44,15 @@ public enum LogTarget {
     /// </summary>
     public class Logger {
 
+        /// <summary>
+        /// Whether all log messages should be display.
+        /// </summary>
+        internal static bool DebugLoggingEnabled {
+            get {
+                return Environment.CommandLine.Contains("-gvh_log_debug");
+            }
+        }
+
         /// <summary>
         /// Filter the log level.
         /// </summary>
@@ -107,7 +116,7 @@ private void LogToFile(string message) {
         /// <param name="level">Severity of the message, if this is below the currently selected
         /// Level property the message will not be logged.</param>
         public virtual void Log(string message, LogLevel level = LogLevel.Info) {
-            if (level >= Level || ExecutionEnvironment.InBatchMode) {
+            if (level >= Level || DebugLoggingEnabled) {
                 switch (level) {
                     case LogLevel.Debug:
                     case LogLevel.Verbose: