some files have different license header

[bildechinger]

We want to include cppcheclipse in our Eclipse-based product, however, we did a licence review and have a few questions.

This cppchecklipse-project is developed under Apache 2.0 license but the following files contain other license artifacts:

• EPL-1.0 in
  https://github.com/kwin/cppcheclipse/blob/master/com.googlecode.cppcheclipse.ui/src/com/googlecode/cppcheclipse/ui/preferences/CheckedTreeEditor.java

• EPL-1.0 in https://github.com/kwin/cppcheclipse/blob/master/com.googlecode.cppcheclipse.feature/feature.xml

• CPL-1.0 in
  cppcheclipse-https://github.com/kwin/cppcheclipse/blob/master/com.googlecode.cppcheclipse.ui/src/com/googlecode/cppcheclipse/ui/preferences/FieldEditorOverlayPage.java

Can you clarify why there are different license artifacts than Apache 2.0?
Have all copyright holders agreed to use Apache 2.0?