Ready to go

-> 'combinations' function, returns the sum of 'dict_len^key_len' from
'key_len' = 0 to 'max_key_len'.
-> ulong type
-> Dict::None
-> Empty treasure constructor (for real-life use), string key
constructor (for educational purposes), that saves a copy of the key to
compare later.
-> Brute::start now asks for max_len and a custom dictionary vector,
that is inserted in the final dictionary vector. May pass a struct for
more flexibility!
-> Treasure::validate now simply compares stored str to passed key.
-> main.cpp does some benchmarking
Merge branch 'master' of https://github.com/aszkid/bruteplus