renameFile: Renames a file (or a directory) atomically/safely
Description
Renames a file (or a directory) atomically/safely,
 by also asserting that it was successfully renamed without side effects.
 If failing to rename and overwrite an existing file, the original file
 is kept.Usage
## S3 method for class 'default':
renameFile(pathname, newPathname, overwrite=FALSE, ..., verbose=FALSE)
Arguments
pathname
The pathname of the file to be renamed.
newPathname
The new pathname.
overwrite
If TRUE and there exists a file with new pathname,
   then it is overwritten. Value
- Returns 
TRUE if the file was successfully renamed.
  If it failed, an exception is thrown.