remove cppname

Created by: jmitrevs

Variable name and cppname are often used interchangeably in the code, not consistently. My understanding is that cppname was meant to be a cleaned up C-legal version of name. Instead of looking at each case where name is used and trying to see if it should be cppname and vice versa, it probably makes sense to just get rid of cppname altogether, and just use name everywhere.

One question is whether we want to include this name cleaning in the Variable.__init__ function:

self.name = re.sub(r'\W|^(?=\d)','_', self.name)

I have not included it. The standard pytests all pass without it.