prepSources: Combines and filters one or more script files into a single...
In USGS-VIZLAB/vizlab: Utilities for building online data visualizations

Return the MD5sum of a deparsed script - this shouldn't change if whitespace or comments change but should change if there's anything substantive

1	prepSources(..., functions, outfile)

`...`	length-1 character strings of R script filenames to be parsed'
`functions`	length-1 character string of 1+ functions to include, or "" to include all functions. The contents of the combined scripts can be optionally filtered to include definitions for only those functions (or R objects) listed here. If there are >1 functions to include, they should be separated by commas wtihin the same string, e.g., ''fetch.cars,cars.helper''
`outfile`	full file path where the combined source file should be written. This will usually be vizlab/remake/scripts/vizitemname.R