trivial change to README to make the gradle wrapper download clearer

README.md

@@ -5,6 +5,7 @@ See our [web site](http://kafka.apache.org) for details on the project.
 You need to have [gradle](http://www.gradle.org/installation) installed.
 
 ### First bootstrap and download the wrapper ###
+    cd kafka_source_dir
     gradle
 
 Now everything else will work

gradlew

@@ -7,7 +7,7 @@
 ##############################################################################
 
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS="-Xmx1024m -Xms256m -XX:MaxPermSize=512m"
+DEFAULT_JVM_OPTS=""
 
 APP_NAME="Gradle"
 APP_BASE_NAME=`basename "$0"`

gradlew.bat

@@ -9,7 +9,7 @@
 if "%OS%"=="Windows_NT" setlocal
 
 @rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS=-Xmx1024m -Xms256m -XX:MaxPermSize=512m
+set DEFAULT_JVM_OPTS=
 
 set DIRNAME=%~dp0
 if "%DIRNAME%" == "" set DIRNAME=.