[#75] Remove reference to BrowserTopComponent.settings from layer.xml

[#75] Remove reference to BrowserTopComponent.settings from layer.xml

The missing file breaks Rails debugging reporting the following message:

  Caused: java.io.FileNotFoundException: jar:file:/.../org-nbgit.jar!/org/nbgit/resources/BrowserTopComponentSettings.xml
    at org.netbeans.JarClassLoader$ResURLConnection.connect(JarClassLoader.java:870)
    at org.netbeans.JarClassLoader$ResURLConnection.getInputStream(JarClassLoader.java:906)
    at org.netbeans.core.startup.layers.BinaryFS$BFSFile.getInputStream(BinaryFS.java:736)
  Caused: java.io.FileNotFoundException

The change should not alter anything, since the component was not
persisted before either.

Also update the gitversioning .settings files to version 0.4 and give
the BrowserTopComponent class a more unique ID: org-nbgit-ui-browser.

Signed-off-by: Jonas Fonseca <fonseca@diku.dk>