If host proved itself down during previous ping check do not try
to execute script, instantly return ERR_DOWN instead.

Script errors now shown correctly in web interface.

 * Activator can use fping to check hosts availability
 * fm.ping_check periodic task
 * PingCheckRequest/PingCheckResponse RPC Messages
 * Activator's ping_check RPC method

 * Script.requires list for interface filters
 * Script constructor accepts profile as first argument of constructor

 * Parameters are encoded and passed via RPC
 * debug-script now accepts optional argument with script parameters

 * Script framework
 * pull_config methods and RPC calls replaced with generalized "script"

 * EventFilterResponse.expire field
 * Activator re-requests event filters after expire seconds

 * Trap filters a generalized to event filters
 * get_trap_filter RPC message substituted by event_filter
 * event_proxy RPC message
 * All events can be proxied to SAE for further processing
 * EventCollector base class
 * TrapCollector and SyslogCollector are subclasses of EventCollector
 * ERR_UNKNOWN_TRAP_SOURCE renamed to ERR_UNKNOWN_EVENT_SOURCE

 * Syslog collector for activator
 * activator/listen_syslog configuration variable
 * Profile.syslog_config_changed
 * syslog_config_changed for Cisco.IOS
 * get_syslog_filter RPC call
 * "Syslog Config" columnt in sa.supported_equipment report

 * noc-activator.conf accepts [activator]/max_pull_config parameter
 * activator returns ERR_OVERLOAD when pull_config limit reached
 * SAE  performs next_pull randomization in case of failure
 * SocketFactory.count_subclass_sockets method

handle correctly rapid connection to local addresses
on SOLARIS 10

 * noc.sa.rpc get_nonce() and get_digest(name,secret,nonce) methods
 * Activator REGISTRED state
 * Activator.auth
 * SAE protocol ERR_AUTH_FAILED, ERR_AUTH_REQUIRED errors
 * SAE protocol AuthRequest/AuthResponse
 * SAE now requires authentication for all methods except register and auth

 * Activator reconnects when connection lost
 * SNMP Trap Listener active only in ESTABLISHED state
 * sa/sae_stream.py moved to sa/rpc.py
 * actions use noc.lib.registry framework
 * Common ActionSocket mixin
 * ActionSockets use noc.lib.registry framework
 * A lot of temporary stubs removed

* Activator accepts SNMP traps now
* SNMP Trap Filtering
* TrapFilterRequest/TrapFilterResponse message
* NotifyTrapConfigChangeRequest/NotifyResponse
* notify_trap_config_change
* Profile.oid_trap_config_changed