Allow catching of exceptions in chained runnables

The user can handle exceptions of a specified type occurring in a chained
runnable by calling `executeCatching` and optionally passing a handler
function.

This is needed needed in order to gracefully stop the execution of a
runnable chain without the exception being caught by Bukkit and
resulting in it being logged as uncaught, while also allowing further
handling of the exception.

gradlew

@@ -82,6 +82,7 @@ esac
 
 CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 
+
 # Determine the Java command to use to start the JVM.
 if [ -n "$JAVA_HOME" ] ; then
     if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
@@ -129,6 +130,7 @@ fi
 if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
     APP_HOME=`cygpath --path --mixed "$APP_HOME"`
     CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    
     JAVACMD=`cygpath --unix "$JAVACMD"`
 
     # We build the pattern for arguments to be converted via cygpath