Update: minor improvements, finish f_file_copy(), add fifo file type

Update: minor improvements, finish f_file_copy(), add fifo file type

Finish implementing the f_file_copy(), adding support for all file types (except unknown).

The documentation for block, character, and FIFO is unclear to me at this time and my attempts to copy using mknod(2) is an educated guess.
Attempt to prevent file type from being passed via the mode_t when doing a copy (currently untested).

Add the appropriate file create functions to implement the copy operations.
Have the copy file copy only the directory itself and not the contents (to copy contents, the fl_directory_copy() function should be used).

The added fifo type is pretty much the same as pipe.
Mixing fifo with pipe terminology ended up being confusing so I opted to create redundant FIFO types to simplify the readability.

Use the word "regular" for a regular file instead of "file".
Using "regular" is a less confusing than using "file" (i.e. Regular File Type vs File File Type).