Updated data_package to create parameters, meshes, and daymet for a huc

[gaobhub]

• Changed some definitions of variables, but not important.
• Added some parameter options to functions, such as meshing.py Line 121.
• Reordered the notebook
• hillslopes.py Lines 209-235: one problem is that "fp_lengths" may not always fall between a bin [(fp_lengths >= bin_start) & (fp_lengths < bin_end)], especially when it gets close to the largest flowpath length. This will result in 0 rasters in that bin, and thus raise the assert [assert(pixel_bin_counts.min() > 0), Line 234]. I changed a little bit here. I added the bin interval until at least the next flowpath length can be located within the bin at the precondition that the total number of bins won't exceed the predesigned "hillslope['num_bins']". But this may make the rest "hillslope['bin_counts']" has 0 elements. So I regulated "hillslope['bin_counts']" to delete the rest 0 spots and thus the "hillslope['num_bins']" may be smaller than the predesigned "hillslope['num_bins']".
• meshing.py Line 86: Because the hillslope['num_bins'] may be changed, the corresponding definitions for mesh may be not right. I changed to line 85. I think this one works better.