Wrong alignment in markup

[Daniel Berjón]

> I'm not top posting.

%When combining text with dynamics, right- or center-align do not seem to work 
%properly (or I am not writing the right code); in default left-align mode, the 
%space between dynamic and text is correct, but in the other two the dynamic is 
%placed too far right:
\version "2.16.0"

\relative c'' {
    a a a a |
    a_\markup {
        \right-align
        {
            sempre
            \dynamic f
        }
    } a a a 
}
%If the dynamic is placed before the text, the problem is even worse and they 
%collide.