remove old Java 7 check

Revise ShellService.name to match ShellService directory if the directory includes -SystemVersion.getOS or -SystemVersion.getArch

Check executable status of shellservice plugins in start. If the ShellService plugin name doesn't correspond to a directory, check plugin name+-$OS-$ARCH and name+$OS.

Adds the ability to use `$OS`  and `$ARCH`  variables in clients.config and plugins.config(updateURL.* only)

otherwise relative to plugin name, as before

Drop requests if previous or next peer is banned
Console: Drop peer when manually banned
Update: Drop peer when banlisted

Clean up configui.js
CSS cleanups for new page TODO
Gitlab #335

Save theme change before form processing so no refresh required
Enable/disable reset and apply buttons on config clicks
Prep for theme picker in wizard

to make it easier to add/remove/reorder pages later