auth_mschap, radius: if radius replies with MS-CHAP-Error attribute send this value in mschap failure message

pppoe: tr101 option to enable/disable tr101 handling

shaper_tbf: do explicit locking over nl_socket_alloc/nl_socket_free due to this functions are not thread-safe

ppp: treat peer's lcp echo request as lcp echo activity and don't drop connection if there is no peer's echo reply

use /proc/sys/fs/nr_open in conjuction with /proc/sys/fs/file-max to determine limit of maximum number of opened files

log_file: write authentication failed session logs to different file (optional)

ppp: default fsm timeout increased to 3 sec.
ppp: accept LCP TermReq/TermAck packets in terminating phase