frontend typos

1. when editing a trigger wihtout dependencies : "No dependences defined" (should be 'dependencies');

2. when editing item key : "net.tcp.service.perf[service <,ip> <,port>] Check performance of service server."
probably should have "service" instead of "server".

3. when editing item key : "proc.mem[<name> <,user> <,mode>] Memory used of process"
should be "used by"

applies both to 1.4.4 and 1.5 trunk.