preferences > bitmap > rendering shows po file headers

PO file headers are shown in Preferences > bitmap > rendering (and will be one more).
This is because the empty strings are used in the followings:

src/ui/dialog/inkscape-preferences.cpp
1471: _page_bitmaps.add_line(false, _(""), _rendering_image_outline, "", _("When active will render images while in outline mode instead of a red box with an x. This is useful for manual tracing."));

share/filters/filters.svg.h:1
<snip> N_("") <snip>

These conflict po header:
#
#: ../share/filters/filters.svg.h:1
#: ../src/ui/dialog/inkscape-preferences.cpp:1471
msgid ""
msgstr ""
"Project-Id-Version: inkscape\n"
"Report-Msgid-Bugs-To: <email address hidden>\n"
<snip>

Version:
trunk-r13348

Build & platform:
Build 2014-05-11 on ArchLinux