Added REXPList
Added REXPPairList
Added login server command
Added attributes
Created several helper functions in unnamed namespace in RPacketEntry_0103 in order to support REXPList and REXPPairList
Removed brackets in README.md as the text within the brackets was not appearing
errorStatus now returns a string describing the error instead of just the error number
Added getTypeName to REXP, which returns a string describing the REXP type