updates for v0.4.0

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: whitebox
 Type: Package
 Title: 'WhiteboxTools' R Frontend
-Version: 0.3.0
+Version: 0.4.0
 Description: An R frontend of the 'WhiteboxTools' library, which is an advanced geospatial data analysis platform developed by Prof. John Lindsay at the University of Guelph's Geomorphometry and Hydrogeomatics Research Group. 'WhiteboxTools' can be used to perform common geographical information systems (GIS) analysis operations, such as cost-distance analysis, distance buffering, and raster reclassification. Remote sensing and image processing tasks include image enhancement (e.g. panchromatic sharpening, contrast adjustments), image mosaicing, numerous filtering operations, simple classification (k-means), and common image transformations. 'WhiteboxTools' also contains advanced tooling for spatial hydrological analysis (e.g. flow-accumulation, watershed delineation, stream network analysis, sink removal), terrain analysis (e.g. common terrain indices such as slope, curvatures, wetness index, hillshading; hypsometric analysis; multi-scale topographic position analysis), and LiDAR data processing. Suggested citation: Lindsay (2016) <doi:10.1016/j.cageo.2016.07.003>.
 Authors@R: person("Qiusheng", "Wu", email = "giswqs@gmail.com", role = c("aut", "cre"))
 Maintainer: Qiusheng Wu <giswqs@gmail.com>

README.md

@@ -129,7 +129,7 @@ d_inf_flow_accumulation(dem, "./flow_accum.tif")
 
 ## Available Tools
 
-The **[WhiteboxTools](https://github.com/jblindsay/whitebox-tools)** library currently contains more than 396 tools, which are each grouped based on their main function into one of the following categories: Data Tools, GIS Analysis, Hydrological Analysis, Image Analysis, LiDAR Analysis, Mathematical and Statistical Analysis, Stream Network Analysis, and Terrain Analysis. The following is a complete listing of available tools, with brief tool descriptions.
+The **[WhiteboxTools](https://github.com/jblindsay/whitebox-tools)** library currently contains more than 406 tools, which are each grouped based on their main function into one of the following categories: Data Tools, GIS Analysis, Hydrological Analysis, Image Analysis, LiDAR Analysis, Mathematical and Statistical Analysis, Stream Network Analysis, and Terrain Analysis. The following is a complete listing of available tools, with brief tool descriptions.
 
 **Data Tools**