Made draft Gui. I am not sure about Listener so need to consult with
Radko before connecting logic with Gui.
Updated with Radko's suggestions in comments.
Added some drawing for legal move checker. Lukases teamwork
Resolved merge conflict
Updated gui for new logic version.
Tried to remove stones from logic, but didn't succeed. Possible error in
LegalMoveChecker when trying to remove stone next to boundary?
Merged newest player_utils with gui 
Corretly erasing stones and legal moves from shown graphical board 
fixed bug of removing stones in logic board in gui model
Updated BoardHistory.java in GUI branch
Fixed Board history duplication problem when adding a new board to
history
Now Minimax is throwing errors.
Added File Chooser
Added total number of stones label
Tried solving merge conflicts with the "new" singleton BoardHistory.
Added a method to count stones when opening file
Fixed test cases, now using history singleton. Deleted bin folder
Merge pull request #5 from radkokotev/player_utils

Minimax implementation with a singleton history.
Added "Now moving" to board label
Moved menu items objects from gui to board.
Merge branch 'gui' of https://github.com/radkokotev/GU_LVL3_TEAM_R_13-14.git into gui
Added action combobox
Began tidying up the Gui code. There will be two different classes for
two different statuses: GuiBoardPlaying and GuiBoardLoose.
GuiBoardPlaying will be board for playing status and GuiBoardLoose for
creating/modifying new/old problems and saving them.
Done GuiBoardPlay.