Crash fix and small improvements for easytag

[David King]

Hi James and pkg-multimedia

Thanks for getting EasyTAG 2.1.10 into Debian. I just installed Debian 
in a virtual machine, so hopefully I can help out a bit with packaging.

There has been one important fix added since 2.1.10 was released, about 
a possible crash while clicking the window close button, and I think 
that it is worth including. To get rid of a buildd warning about hidden 
compiler flags, I disabled silent build rules. appdata-tools is now in 
experimental, so I added the dependency.

I am still quite new to Debian packaging, so reviews are very welcome.

Thanks