Include SLF4J from Juno into Indigo TP

M2E's XML Editor requires SLF4J 1.6.2+ which is missing in Indigo:

    [ERROR] Cannot resolve project dependencies:
    [ERROR]   Software being installed: org.eclipse.m2e.feature.feature.group 1.4.0.20130601-0317
    [ERROR]   Missing requirement: org.eclipse.m2e.editor.xml 1.4.0.20130601-0317 requires 'bundle org.slf4j.api 1.6.2' but it could not be found
    [ERROR]   Cannot satisfy dependency: org.eclipse.m2e.feature.feature.group 1.4.0.20130601-0317 depends on: org.eclipse.m2e.editor.xml [1.4.0.20130601-0317]