[yocto] switch between denzil and edison

[Jim Abernathy]

I just build an Ubuntu 12.04 LTS development system and installed the 
required packages based on the current 1.2 QS Guide.  On Denzil based 
BSP that works as expected.

However, I needed to switch back to edison.  When I tried to bitbake an 
image I received errors that stated a need for bash and not dash (just 
like the old days).  Also it needed a package 'cvs'.

Can I assume that bash is supported if I move back to working on the 
denzil release??

Can I assume installing cvs will not interfere with the denzil release?

Jim A