Added behavior when solution is found
Added function getMovedTile

This function returns the tile, which moved (this tile is not zero, it
is the one that last round switched with zero tile). We search for it
like that:
1) find position of zero tile in current state
2) look at this position in previous state
Commented code

Added better comments of code (documentation of function, structure)
New function printSolution, removed outputs

Function printSolution prints sequence of movess to get from initial
state to goal state. (format: number. [movedTile] MOVE_DIRECTION)
Changed command line parameter
Added checking of input

If input is something else than numbers, spaces and semicolons, input is
marked as malformed
Corrected function getRowsCount

It didn't work well because I misused || x && (I also used bad condition
with isdigit)
Added use of global variable row instead of sizeof

Now it works for 3x3 puzzle (when using sizeof, it worked only for 4x4
puzzle)