findPandoc: Locates the pandoc executable
Description
Locates the pandoc executable on the current system.
Usage
# S3 method for default
findPandoc(mustExist=TRUE, ..., verbose=FALSE)
Arguments
mustExist
If TRUE, an exception is thrown if the executable
     could not be located.
Value
Returns the pathname to the executable, or NULL if not found.
Details
The executable is searched for as follows:
Sys.which("pandoc")