Use profile to customize tycho version.

Since tycho 0.25.0 is introduced in eclipse Neon, it's still not
supported in Mars. So Mars build still uses 0.22.0 and latest one uses
0.25.0.

pom.xml

@@ -9,7 +9,6 @@
 	<properties>
 		<birt.version>4.6.0</birt.version>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<tycho.version>0.25.0</tycho.version>
 		<Replace_By_Date>v${maven.build.timestamp}</Replace_By_Date>
 		<!--<build>v${maven.build.timestamp}</build>-->
 		<maven.build.timestamp.format>yyyyMMdd-HHmm</maven.build.timestamp.format>
@@ -25,6 +24,7 @@
             </activation>
             <properties>
                 <eclipse.release.name>neon</eclipse.release.name>
+                <tycho.version>0.25.0</tycho.version>
                 <eclipse.repo.url>http://download.eclipse.org/eclipse/updates/4.6milestones/</eclipse.repo.url>
                 <emf.repo.url>http://download.eclipse.org/modeling/emf/emf/updates/2.12milestones/</emf.repo.url>
                 <gef.repo.url>http://download.eclipse.org/tools/gef/updates/milestones/</gef.repo.url>
@@ -42,7 +42,8 @@
         <profile>
        	    <id>mars</id>
             <properties>
-		<eclipse.release.name>mars</eclipse.release.name>
+				<eclipse.release.name>mars</eclipse.release.name>
+				<tycho.version>0.22.0</tycho.version>
             	<eclipse.repo.url>http://download.eclipse.org/eclipse/updates/4.5/</eclipse.repo.url>
                 <emf.repo.url>http://download.eclipse.org/modeling/emf/emf/updates/2.11/</emf.repo.url>
                 <wtp.repo.url>http://download.eclipse.org/webtools/repository/mars/</wtp.repo.url>