DynamicTextSpanner spacing

[Erika Pirnes]

I would like the dotted line of the crescendo to start a bit later and end a 
bit earlier. It is too close to "cresc.", in my opinion at least. And sometimes 
too close to the "f" as well. (A tiny detail, for sure, but it looks annoying.) 
Any ideas?

Minimal example below. (The problem with "f" didn't appear without repeting the 
passage.)

\version "2.18.2"

music = \relative c' {
  \repeat unfold 5{c8 \p \cresc d e f g a b4 c8 \f b c2.}
}

\score{
  \new Staff {\music}

  \layout{
    \context{
      \Score
      \override DynamicTextSpanner.style = #'dotted-line
      \override DynamicLineSpanner.staff-padding = #3
    }
  }
}

Thank you!
Erika