make the build work for SDK product

Basically I removed everything that was not found and looked suspicious
to me

Author: jan

io.sloeber.product.sdk/sdk.product

@@ -206,7 +206,6 @@ United States, other countries, or both.
    </plugins>
 
    <features>
-      <feature id="org.eclipse.e4.rcp.source" installMode="root"/>
       <feature id="org.eclipse.e4.rcp" installMode="root"/>
       <feature id="org.eclipse.ecf.core.feature" installMode="root"/>
       <feature id="org.eclipse.emf.common" installMode="root"/>
@@ -219,12 +218,9 @@ United States, other countries, or both.
       <feature id="org.eclipse.equinox.p2.rcp.feature" installMode="root"/>
       <feature id="org.eclipse.equinox.p2.user.ui" installMode="root"/>
       <feature id="org.eclipse.help" installMode="root"/>
-      <feature id="org.eclipse.jdt.source" installMode="root"/>
       <feature id="org.eclipse.jdt" installMode="root"/>
       <feature id="org.eclipse.jgit" installMode="root"/>
-      <feature id="org.eclipse.pde.source" installMode="root"/>
       <feature id="org.eclipse.pde" installMode="root"/>
-      <feature id="org.eclipse.platform.source" installMode="root"/>
       <feature id="org.eclipse.platform" installMode="root"/>
       <feature id="org.eclipse.rcp" installMode="root"/>
       <feature id="org.eclipse.rse.core" installMode="root"/>
@@ -234,22 +230,12 @@ United States, other countries, or both.
       <feature id="org.eclipse.rse.ssh" installMode="root"/>
       <feature id="org.eclipse.rse.telnet" installMode="root"/>
       <feature id="org.eclipse.rse" installMode="root"/>
-      <feature id="org.eclipse.equinox.p2.core.feature.source" installMode="root"/>
-      <feature id="org.eclipse.equinox.p2.user.ui.source" installMode="root"/>
-      <feature id="org.eclipse.ecf.filetransfer.httpclientjava.feature" installMode="root"/>
       <feature id="org.eclipse.egit" installMode="root"/>
       <feature id="org.eclipse.jgit.http.apache" installMode="root"/>
       <feature id="org.eclipse.jgit.gpg.bc" installMode="root"/>
       <feature id="org.eclipse.jgit.ssh.apache" installMode="root"/>
       <feature id="org.eclipse.equinox.core.feature" installMode="root"/>
       <feature id="org.eclipse.egit.gitflow.feature" installMode="root"/>
-      <feature id="org.eclipse.help.source" installMode="root"/>
-      <feature id="org.eclipse.rcp.source" installMode="root"/>
-      <feature id="org.eclipse.equinox.p2.rcp.feature.source" installMode="root"/>
-      <feature id="org.eclipse.equinox.core.feature.source" installMode="root"/>
-      <feature id="org.eclipse.equinox.p2.extras.feature.source" installMode="root"/>
-      <feature id="org.eclipse.ecf.filetransfer.feature" installMode="root"/>
-      <feature id="org.eclipse.ecf.filetransfer.httpclient5.feature" installMode="root"/>
       <feature id="org.eclipse.justj.openjdk.hotspot.jre.full" installMode="root"/>
       <feature id="org.eclipse.m2e.pde.feature" installMode="root"/>
    </features>