Added 2D integer array test to unit tests
Added get_array_2d_integer() to fson_path_m module, for parsing 2D integer arrays
Added 2D real array test to unit tests
Added get_array_2d_real(), for parsing 2D real arrays
Added 2D double array test to unit tests
Added get_array_2d_double(), for parsing 2D double arrays
Added 2D logical array test to unit tests
Added get_array_2d_logical(), for parsing 2D logical arrays
Added 2d array to array example in readme
In get_array_2d(), added check to make sure all rows are the same length
Cosmetic edit to get_array_2d()