Creates/modifies/deletes affil list of a site.
Usage: <cmd> sitename section [affil1] [affil2 ...]
If no affils are specified, then it list affil list of sitename/section.
If an affil is not found in the list, the affil is being added.
If the affil is found in the chain, the affil is being removed.
If the list gets empty, it is removed.
Examples:
<cmd> SITE MP3 GRP1 GRP2 <- GRP1, GRP2 are added.
<cmd> SITE MP3 GRP2 GRP3 <- GRP2 is removed, GRP3 is added (so list has GRP1 and GRP3 now)
<cmd> SITE MP3 GRP1 GRP3 <- list is removed.