add catching exceptions
implements set_config and get_config with zookeeper.
jubaconfig is a command line tool that set/get config data from zookeeper.
don't use not statement
change loglevel: port conflict
Catch bad_cast of fv_converter config and throw it as jubatus_exception
Catch end_of_data and parse_error parsing converter config
add try/catch/throw at each method in *_impl.cpp

When jubatus throw JUBATUS_EXCEPTION, we should output WARNING log
and return exception string to some clients.
add log
Merge branch 'feature/log' of http://github.com/jubatus/jubatus into feature/log
add spaces to stacktrace in exception
output log to file
specify symbolic link name
print messages on stderr when command arguments error occurred
add logdir option
specify zklog location, add logdir option to jubactl and jubavisor
set filename extension ".log"
add pid for filename of zklog
Move make_fv_conveter from server_util.cpp to converter_config.cpp
Change error messages for parse error
Regenerate *_keeper.cpp (generator: 5386ec48795269d799e578b04f43a43a70e95e9b)

When keeper#run throws jubatus_exception, we should output FATAL log instead of std::cout.