Comment 3 for bug 1255830

The new header layout has been planned in advanced. From the official tutorial:
<quote>

 1. Locate the FreeType 2 include directory.

 2. Include the file named ft2build.h.

 3. Include the main FreeType 2 API header file.

    You should do that using the macro FT_FREETYPE_H, like in the
    following example:

    #include <ft2build.h>
    #include FT_FREETYPE_H

    FT_FREETYPE_H is a special macro defined in the file ftheader.h. It
    contains some installation-specific macros to name other public
    header files of the FreeType 2 API.

<...>

 NOTE: Starting with FreeType 2.1.6, the old header file inclusion scheme
 is no longer supported. This means that you now get an error if you do
 something like the following:

   #include <freetype/freetype.h>
   #include <freetype/ftglyph.h>

</quote>
<http://www.freetype.org/freetype2/docs/tutorial/step1.html>

Possibly Inkscape needs to check for freetype >= 2.1.6 … (?)