Added messages. Fixed some bugs. Added TODO notes

Added messages from Messenger.
Added "...enter your name..." message.
Changes in ScoreBoard messages.
Change in RandomNumberGenerator:
- bug cannot return number starting with zero because the parse method -
fixed - now returning string.
Removed is first digit zero check.
Added ResetGameVariables method.
Bug with help command:
- enter into an infinite loop after 4-th call - fixed.
- cannot enter guess number starting with zero - fixed.
Bug in ScoreBoard class - used sorted dictionary - cannot have several
player with same score - added TODO note.