Added new function for box geometry, including:
- AreaBox
- CriticalDepthBox
- CulvertHW_Box (use chart/scale no.s 81, 82, or 83 from FHWA HDS-5)
- DepthManningBox
- FroudeNoBox
- HydRadBox
- QManningBox
- SlopeManningBox
- TopWidthBox
- WetPerimBox
Made minor updates to the natural channel functions including:
- unlimited length of ranges can be used
- blanks and non-numeric values are automatically filtered out
Note that the help file for the new functions has not been updated yet.