[l10n] Update Japanese translation

Merge latest pot
[l10n] Update Japanese translation

Modify the About label
Fix alphabet combo box

Previous alphabets used are now remembered. (introduced in df5eebe2)
Updated Norwegian bokmål translation
Updated Polish translation
Updated Indonesian translation
Make Direct Mode available from toolbar and menu

Not just from the command line.  (i.e. enable the work done
in 5e640558)
Updated Polish translation
Updated Slovenian translation
GCC 4.6 compile fix:

     * Most libstdc++ standard headers have been changed to no longer
       include the cstddef header as an implementation detail. Code that
       relied on that header being included as side-effect of including
       other standard headers will need to include cstddef explicitly.

(iconv.h include stddef.h)
Updated British English translation
Updated Indonesian translation
Updated Lithuanian translation
Updated Serbian translation
Updated Spanish translation
Improve direct mode (the application style) toggle

Make the direct mode adjustments that were in

  dasher_main_setup_window_style()
  dasher_main_load_interface()

namely, hide the text box, stick dasher to all desktops and
refuse focus.

We'll have to find another name for direct mode the application
style, as one of the button modes is already called direct mode.
Some more std::size_t while we're at it.
headers already included in Common/Common.h
g/c DASHER_WIN32 and DASHER_WINCE, therefore Platform.h

Conjecture: Windows programmers are used to _WIN32 being defined by the
compiler and simply use it rather than hunting for the DASHER_* defines
in Platform.h. Evidence for this is e.g. DASHER_WINCE and _WIN32_WCE
being used in the same way in DasherWindow.cpp.
The point of the TEXT() macro is to do the right thing wrt UNICODE.