add function to load multiple configuration values
[MINOR_CHANGE] remove unused import statements
add a new enum to represent mining unit
add a new node to have mining unit
add mining unit to the config class
add a function to load mining unit
update mining main
add a new option to represent project name
replace database name with project name
add a shortened name of the mining strategies
make current strategies implement WriteFileMiningStrategy
add function to roll the output file name