nsis: sync wording with the uninstaller section
nsis: make new strings translatable
nsis: remove dead uninstaller code
nsis: remove unused string
Fixed parsing SubRip subtitles with missing msecs.

This patch fixes SubRip subtitles parsing with missing microseconds.
This patch also makes redundant SUB_TYPE_SUBRIP_DOT format as both
delimiters (dot and comma) are now supported equally.

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>