0.5.1 release

[Bouke Woudstra]

Hi there,

Just an update to get us through the summer. As noticed before, the
development has been going quite slowly for about a half year. However, there
are some things fixed and improved, so a new release seems to be in place.

Changelog:
* important fix that prevents creating corrupted wav files
* move over to one single language file
* make ruby-gettext optionally
* single file ripping supported
* cuesheet support
* some small fixes all over the place

Have fun!

Bouke Woudstra
Rubyripper developer