SSS Shader added in 'Swap Shaders', shortucts conflicts addressed.

- New Subsurface Scattering Shader has been added, so Nodes Efficiency Tools 'Swap Shaders' needed to be updated to take SSS into account.
- Revision 55718 changed keyboard shortcuts for 'Find nodes' and 'Make Links with Replace'.
    (Ctrl-F for 'Find Nodes' and Shift-F for 'Make Links with Replace')
    Those changes caused shortcuts conflicts with Nodes Efficiency Tools 'Link Active To Selected'.
    New shortcuts for 'Link Active to Selected are as follows:
        BACK_SLASH - call 'Link Active to Selected' menu
        K - link to all selected, don't replace links.
        Shift-K - link to all selected, replace links.
        QUOTE - link to selected when node name matches, don't replace links.
        Shift - QUOTE - link to selected when node name matches, replace links.
        SEMI_COLON - link to selected when outputs names matche, don't replace links.
        Shift - SEMI_COLON - link to selected when outputs names match, replace links.

'K' key is used as it's the last letter of 'LINK'. QUOTE and SEMI_COLON are used as they are close to BACK_SLASH that call main 'Link Active to Selected' menu.
Any suggestions for using different keys are more than welcome.