Regexp for GfsVariable

From Gerris

This can be used within emacs to replace the obsolete GFS_VARIABLE macro with GFS_VALUE. For example:

GFS_VARIABLE (cell, gls->p->i)

with

GFS_VALUE (cell, gls->p)

The search regexp is

GFS_VARIABLE *(\(.*\), *\(.*\)->i *)

and the replacement is

GFS_VALUE (\1, \2)