IP Traffic: cstats V2
* cstats now uses an AVL balanced binary tree for internal structures and data storage instead of plain/static arrays, used by previous versions
* enhancements on the data/storage subsystem, improved resilience
* new nvram var/option cstats_all: enable auto-discovery of new addresses for IP Traffic monitoring (admin-iptraffic.asp)
* IP Traffic Real-Time Graph updated accordingly (ipt-24.asp)
* removed unused nvram var cstats_data (saving to NVRAM was never supported anyways)
* changed default value for nvram cstats_include (no longer needed)