Unhelpful error on absence of gettext

[bobf]

When gettext is not installed the build output (for me) is as follows:

scons: Reading SConscript files ...
Checking for pkg-config... (cached) yes
Checking for libavformat... (cached) yes
Checking for libavutil... (cached) yes
Checking for libavcodec... (cached) yes
Checking for sqlite3... (cached) yes
Checking for libexif... (cached) yes
Checking for id3tag... (cached) yes
Checking for flac... (cached) yes
Checking for ogg... (cached) yes
Checking for vorbis... (cached) yes
Checking for ogg... (cached) yes
Checking for C library pthread... (cached) yes
Checking for C library jpeg... (cached) yes
Checking for C header file sys/inotify.h... (cached) yes
Checking for C header file iconv.h... (cached) yes
Checking for C header file libintl.h... (cached) yes
scons: done reading SConscript files.
scons: Building targets ...
Compiling: po/da.po
sh: check-domain: not found
Installing: po/da.mo => /usr/share/locale/da/LC_MESSAGES/minidlna.mo
scons: *** [/usr/share/locale/da/LC_MESSAGES/minidlna.mo] po/da.mo: No such file or directory
scons: building terminated because of errors.

I think you want to check that WhereIs("msgfmt") in tools/gettext.py doesn't return None and provide a more helpful error if it does.