wde0924/X-STILT: X-STILT (allow for multiple programs)

Changes in the features from X-STILTv1.0.1:

1. Automatically distribute all selected OCO-2 soundings (i.e., X-STILT receptors) to different STILT copies; with a required subroutine of "/src/xstiltR/allocate.recp()".

2. Automatically allow for more efficiency in generating column back trajectories based on multiple copies; automatically write a bash script for job submission on Univ. of Utah's CHPC, with a required subroutine of "/src/xstiltR/write.bash()".

3. Allow for subsetting and creating ODIAC emission given a lat/lon domain from its global 1kmx1km GeoTIFF file (downloaded from its official webpage @ http://db.cger.nies.go.jp/dataset/ODIAC/DL_odiac2017.html); with required subroutines of "/src/xstiltR/convert.tif2nc.odiac.r & area.r"