This commit changes the term "folder" to "directory" in every
instance where the first is used in an example description, but the
second is used in the example code, and vice versa.
* rm: various tweaks for clarity; add -v
changed some descriptions and tokens to make the meaning of each command clearer, and facilitate memorization of the flags
added the -v (verbose) option
* use a more intuitive pattern for the -i option
Fixes#310
Some files had no newlines, some had 1 newline and some more than 1 newline.
Normalize them all to have only 1 newline at the end of all files.