Finished setting up the build system.
Implemented the overall styles of the board, and implemented a module to generate the initial data set.
Implemented the guess value widget. The widget displays a list of available numbers to choose from and inserts the chosen number into the board.

Other changes included in this commit:
- Added box-shadow to the sub square that is being selected.
- Added SudokuUtils, a module that contains all the util functions that could be reused throught the app.
- Modified the sudoku3x3table and sudokuBoard's templates to make the app easier to select the elements based on the row and column data.
- Added single side border radius mixins to vendors.scss
Implemented SudokuChecker, a module that is responsible for checking the state of the board. Check if the rows/columns/sub tables are not violating rules, as well as checking if the game is solved.

- Turns the violating row, column, or sub table into red va ues if duplicated values are found. Added the royal red color in colors.scss.
- Added sub square selectors util functions in SudokuUtils.
Added the feature 'double click to remove the guess value'.
Added the feature that turns the row/column/subtable that is violating the rules in red.
Disabled selection inside the sub square.
Added instruction to remove the guess.
Changed the font to 'Open sans' and set the font-sizes.
Added the pubsub lib to handle the event handlings between modules.
Added the end of game banner widget when the game is over.
Regenerates a new board if the player elects to play a new game.
Fixed a bug that non-selectable values in the guess value widget being being selectable functional wise.
Added animations to the initial values, instruction, and the enf of game banner.
Added Grunt option 'dist' to produce minified js file.