Creates a directory including any necessary but nonexistent parent directories.
# S3 method for default
mkdirs(pathname, mustWork=FALSE, maxTries=5L, ...)Returns TRUE if the directory was successfully created,
 otherwise FALSE.
 Note that if the directory already exists, FALSE is returned.
A character string of the pathname to be checked.
If TRUE and the directory does not already exists or
   is failed to be created, an error is thrown, otherwise not.
A positive integer specifying how many times the
    method should try to create a missing directory before giving up.
Not used.
On very rare occasions, we have observed on a large shared file
  system that if one tests for the existence of a directory immediately
  after creating it with dir.create(), it may appear not
  to be created.  We believe this is due to the fact that there is a
  short delay between creating a directory and that information being
  fully propagated on the file system.  To minimize the risk for such
  false assertions on "slow" file systems, this method tries to create
  a missing directory multiple times (argument maxTries) (while
  waiting a short period of time between each round) before giving up.
Henrik Bengtsson
Internally dir.create() is used.