intra_substitutionCS_isomerization accessibility

-rearrangement of entries to pass accessibility tests
-*3 subtree was overspecified for many groups. I have removed many of these groups and reduced the rest. This applies to all groups below CdsJ in that subtree.
-Add two groups XSR4J_SS_Cs, XSR4J_SS_Ss which further specify atomtypes on backbones to accomodate rules
-change rule number 2 to use groups XSR3J_S;C-HHH;CsJ-HH. I had to go back to commit 5f2c3c1 to see what the original intent was, but I'm fairly sure it is now correct