[Click] the released version or CVS version

[Yihong Zhou]

Even though I have been working on click for some days, I still have a
couple of basic questions.
 
If we want to develop new elements based on click, should we install the
CVS version?  Is that because the CVS version is updated more often, and
contains the source files that have not been released yet?
 
For the linux OS, sine the patches do not support Redhat kenerl, would
they support Debian kernel?
 
Is "Spinlock" a kind of mutex? 
 
Thanks a lot.