Log Message:
Update to 0.48

Changelog:
        ___  _  _    ___
__   __/ _ \| || |  ( _ )
\ \ / / | | | || |_ / _ \  Thanks for the patches, guys
 \ V /| |_| |__   _| (_) |
  \_/  \___(_) |_|  \___/      (released 2016-06-17)

SGML:
 * Use OpenSP as an underlying engine instead of the deprecated SP
   Thanks to Neil Roeth (Debian's 809477, 280882)

Translations:
 * Update Japaneese, thanks to Takuma Yamada.
 * Fix formating issue in pt translation (noticed by Lintian).