\easyHeadsOn sharp/flat collisions (lilypond 2.13.7)

[Martin Tarenskeen]

The following example demonstrates a problem with \easyHeadsOn in combination
with sharps or flats. This problem was introduced recently: I'm having no such
problems with lilypond 2.12.3.

\version "2.13.7"
\relative c' {
  c d ees fis
  \easyHeadsOn
  c d ees fis
}