Updated readme and the version of java and some plugins & libraries.

Change-Id: I71c3906e5ef10451bf6dbc85dd563e37bca69ded
diff --git a/Changes b/Changes
index 026930e..dd69c3c 100644
--- a/Changes
+++ b/Changes
@@ -1,10 +1,12 @@
-0.59.0 2019-11-06
+0.59.0 2019-11-07
     - [bugfix] Fix offset retrieval in concurrent searches
       (diewald)
     - [cleanup] Removed deprecated numberOf() method from index
       (diewald)
     - [bugfix] Fix offset retrieval in concurrent getMatchInfo requests
       (diewald)
+    - Updated readme and the version of java and some plugins & libraries. 
+      (margaretha)
 
 0.58.7 2019-09-16
     - [bugfix] Fix the behaviour of negative operands in virtual
diff --git a/Readme.md b/Readme.md
index 47ddad2..79e563f 100644
--- a/Readme.md
+++ b/Readme.md
@@ -46,7 +46,7 @@
 
 ## Prerequisites
 
-Java 7 or 8 SDK,
+Java 8 (OpenJDK or Oracle JDK),
 [Git](http://git-scm.com/),
 [Maven 3](https://maven.apache.org/).
 Further dependencies are resolved using Maven.
diff --git a/pom.xml b/pom.xml
index 74a395d..b0bed01 100644
--- a/pom.xml
+++ b/pom.xml
@@ -59,6 +59,7 @@
 	</developers>
 
 	<properties>
+	    <java.version>1.8</java.version>
 		<jersey.version>2.15</jersey.version>
 		<jackson.version>[2.9.5,)</jackson.version>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
@@ -206,12 +207,12 @@
 		<dependency>
 			<groupId>commons-lang</groupId>
 			<artifactId>commons-lang</artifactId>
-			<version>2.3</version>
+			<version>2.6</version>
 		</dependency>
 		<dependency>
 			<groupId>commons-cli</groupId>
 			<artifactId>commons-cli</artifactId>
-			<version>1.3.1</version>
+			<version>1.4</version>
 		</dependency>
     	<dependency>
 		    <groupId>commons-io</groupId>
@@ -226,20 +227,20 @@
 		<plugins>
 			<plugin>
 				<artifactId>maven-compiler-plugin</artifactId>
-				<version>2.5.1</version>
+				<version>3.8.1</version>
 				<inherited>true</inherited>
 				<configuration>
 				    <argLine>-Xms512m</argLine>
 					<showWarnings>true</showWarnings>
-					<source>1.7</source>
-					<target>1.7</target>
+					<source>${java.version}</source>
+					<target>${java.version}</target>
 				</configuration>
 			</plugin>
 
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-shade-plugin</artifactId>
-				<version>2.4.1</version>
+				<version>3.2.1</version>
 				<executions>
 					<execution>
 						<id>indexer</id>
@@ -283,7 +284,7 @@
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-surefire-plugin</artifactId>
-				<version>2.22.1</version>
+				<version>2.22.2</version>
 				<configuration>
           		    <useSystemClassLoader>false</useSystemClassLoader>
           		    <argLine>-Xmx512m</argLine>
@@ -305,16 +306,16 @@
 				<configuration>
 					<configFile>${project.basedir}/Format.xml</configFile>
 					<overrideConfigCompilerVersion>true</overrideConfigCompilerVersion>
-					<compilerSource>1.7</compilerSource>
-					<compilerCompliance>1.7</compilerCompliance>
-					<compilerTargetPlatform>1.7</compilerTargetPlatform>
+					<compilerSource>${java.version}</compilerSource>
+					<compilerCompliance>${java.version}</compilerCompliance>
+					<compilerTargetPlatform>${java.version}</compilerTargetPlatform>
 				</configuration>
 			</plugin>
 
 			<plugin>
 				<groupId>org.codehaus.mojo</groupId>
 				<artifactId>exec-maven-plugin</artifactId>
-				<version>1.2.1</version>
+				<version>1.6.0</version>
 				<executions>
 					<execution>
 						<goals>