Remove customize-alists

[jabranham]

Usually this means setting variables in major modes, but may be on a case-by-case basis. As discussed in #616

• remove ess-setq-vars-local
• ess-custom.el:2857:(defvar ess-customize-alist nil
• ess-custom.el:2864:(defvar ess-local-customize-alist nil
• ess-gretl.el:460:(defvar gretl-customize-alist
• ess-inf.el:116:(defun inferior-ess (&optional ess-start-args customize-alist no-wait)
• ess-julia.el:303:(defvar ess-julia-customize-alist
• ess-r-gui.el:110:(defvar Rgui-customize-alist
• ess-r-mode.el:333:(define-obsolete-variable-alias 'R-customize-alist 'ess-r-customize-alist "ESS 18.10.2")
• ess-r-mode.el:334:(defvar ess-r-customize-alist
• ess-r-package.el:39:(defvar ess-r-customize-alist)
• ess-rd.el:39:(defvar ess-r-customize-alist)
• ess-sas-a.el:32:(defvar SAS-customize-alist)
• ess-sas-d.el:178:(defvar SAS-customize-alist
• ess-sas-d.el:298: (setq-default ess-customize-alist SAS-customize-alist)
• ess-sp6-d.el:69:(defvaralias 'S+6-customize-alist 'S+-customize-alist)
• ess-sp6-d.el:70:(defvar S+-customize-alist
• ess-stata-mode.el:66:(defvar STA-customize-alist
• essd-els.el:53:(defvar S+elsewhere-customize-alist
• grep through the source code for stuff like cust alist

[vspinu]

Before we proceed further with this goal, lets compile a list of relevant variables that represent our "state". This will be needed in order to move the state from one buffer to another, which was historically one function of customize alist.

We move state in a few places already (mainly process name). I think we should replace that with a generic ess-move-state or something.