Adds a new copySign command that copies all info about a sign, including current lines, placeholders, waxed state, dye for each side, and glow state for each side.
Renames editSign to setSignLine to avoid collision with EssentialsX's editSign
Reduces viewSign to a single command
Makes viewSign display the looked at sign, instead of creating a session
Adds some additional messages
Adds missing documentation to the README
