Set version on all projects in preparation of the upcoming 1.5.7

release.

[Build]

org.lamport.tla.toolbox.product.product/org.lamport.tla.toolbox.product.product.product

 <?xml version="1.0" encoding="UTF-8"?>
 <?pde version="3.5"?>
 
-<product name="TLA+ Toolbox" uid="org.lamport.tla.toolbox.product.product" id="org.lamport.tla.toolbox.product.standalone.product" application="org.lamport.tla.toolbox.application" version="1.5.6.qualifier" useFeatures="true" includeLaunchers="true">
+<product name="TLA+ Toolbox" uid="org.lamport.tla.toolbox.product.product" id="org.lamport.tla.toolbox.product.standalone.product" application="org.lamport.tla.toolbox.application" version="1.5.7.qualifier" useFeatures="true" includeLaunchers="true">
 
    <aboutInfo>
       <image path="/org.lamport.tla.toolbox.product.standalone/images/splash_small.png"/>
       <text>
          TLA+ Toolbox provides a user interface for TLA+ Tools. 
 
-This is Version 1.5.6 of 29 January 2018 and includes:
+This is Version 1.5.7 of 29 January 2018 and includes:
   - SANY Version 2.1 of 23 July 2017
   - TLC Version 2.12 of 29 January 2018
   - PlusCal Version 1.8 of 07 December 2015
@@ -83,7 +83,7 @@ openFile
       <plugin id="org.eclipse.update.configurator"/>
       <plugin id="org.lamport.tla.toolbox.jclouds" autoStart="true" startLevel="4" />
       <plugin id="sts" autoStart="true" startLevel="4" />
-      <property name="eclipse.buildId" value="1.5.6" />
+      <property name="eclipse.buildId" value="1.5.7" />
    </configurations>
 
    <repositories>

org.lamport.tla.toolbox.product.product/pom.xml

@@ -19,7 +19,7 @@
     <!-- Align product.version with the version in 
          org.lamport.tla.toolbox.product.product.product
          product.version. -->
-    <product.version>1.5.6</product.version>
+    <product.version>1.5.7</product.version>
     <!-- Format build timestamp to adhere to the Debian package guidelines -->
     <maven.build.timestamp.format>yyyyMMdd-HHmm</maven.build.timestamp.format>
     <product.build>${maven.build.timestamp}</product.build>

org.lamport.tla.toolbox.product.standalone/plugin.xml

@@ -30,7 +30,7 @@
          </property>
          <property
                name="aboutText"
-               value="TLA+ Toolbox provides a user interface for TLA+ Tools. &#x0A;&#x0A;This is Version 1.5.6 of 29 January 2018 and includes:&#x0A;  - SANY Version 2.1 of 23 July 2017&#x0A;  - TLC Version 2.12 of 29 January 2018&#x0A;  - PlusCal Version 1.8 of 07 December 2015&#x0A;  - TLATeX Version 1.0 of 20 September 2017&#x0A;&#x0A;Don&apos;t forget to click on help.  You can learn about features that you never knew about or have forgotten.&#x0A;&#x0A;Please send us reports of problems or suggestions; see https://groups.google.com/d/forum/tlaplus .">
+               value="TLA+ Toolbox provides a user interface for TLA+ Tools. &#x0A;&#x0A;This is Version 1.5.7 of 29 January 2018 and includes:&#x0A;  - SANY Version 2.1 of 23 July 2017&#x0A;  - TLC Version 2.12 of 29 January 2018&#x0A;  - PlusCal Version 1.8 of 07 December 2015&#x0A;  - TLATeX Version 1.0 of 20 September 2017&#x0A;&#x0A;Don&apos;t forget to click on help.  You can learn about features that you never knew about or have forgotten.&#x0A;&#x0A;Please send us reports of problems or suggestions; see https://groups.google.com/d/forum/tlaplus .">
          </property>
          <property
                name="aboutImage"

org.lamport.tla.toolbox.product.standalone/src/org/lamport/tla/toolbox/ui/intro/ToolboxIntroPart.java

@@ -175,7 +175,7 @@ public class ToolboxIntroPart extends IntroPart implements IIntroPart {
 
 		final Label lblVersion = new Label(outerContainer, SWT.WRAP);
 		lblVersion.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, false, false, 2, 1));
-		lblVersion.setText("Version 1.5.6 of 29 January 2018");
+		lblVersion.setText("Version 1.5.7 of 29 January 2018");
 		lblVersion.setBackground(backgroundColor);
 	}