Kfs client lib: allow to set client configuration parameters or configuration file name with environment variable. If
QFS_CLIENT_CONFIG_<meta host>_<meta port> is set then it will be assumed to contain the configuration, if such environment variable
doesn't exit the QFS_CLIENT_CONFIG variable, if exists will be used. The FILE: prefix denotes the name of the configuration file, if no
FILE: prefix exists then it is assumed that the environment variable contains space separated key=value parameter pairs.