Make Artist Name Case Insensitive

[GoogleCodeExporter]

1) Please describe the steps to reproduce the situation:
a.Insert CD to be ripped and get metadata from Freedb with artist's name in 
mixed case, i.e. "The Doors".  Rip and get new folder named "The Doors" with 
album contents in appropriate folder/file structure.

b. Insert another CD to be ripped and get metadata from Freedb with artist's 
name in upper case, i.e. "THE DOORS". Rip and get another folder named "THE 
DOORS with album contents in appropriate folder/file structure.

c.

2) What is the expected output? What do you see instead?
Make Artist's name case insensitive when creating the ripped file structure.  
This way, if an artist folder already exists in any case, rubyripper will place 
the ripped output under that existing folder instead of creating a new folder. 

3) What version of rubyripper are you using? 0.6.2-1 (from getdeb)
On what operating system? Unbuntu 12.04
The gtk2 of commandline interface?

4) Is this not already fixed with the latest & greatest code? See for
instructions the Source tab above.

5) Does the problem happen with all discs? If not, please attach
the output of cdparanoia -Q with a disc that gives trouble.

6) Please explain why this change is important for you. Also, how many
users would benefit from this change?
Users don't end up with multiple artist folders for the same artist, i.e.
The Doors
The DOORS
THE DOORS

Please provide any additional information below. The more usefull
information provided, the sooner the issue will be fixed.

Note that ruby versions older than 1.9 are no longer supported. You are
advised to upgrade instead.

Original issue reported on code.google.com by sca...@gmail.com on 24 Nov 2013 at 5:00