Remove extraneous whitespace

Remove extra space at the end of the program description.
Restructure code

Massive rewrite here. Sorry. Should be more robust, though.
Add --format option

Let the user specify different output formats. Available options
are currently "human" and "nbt"
Update README

Refer to twoolie by his full name and add a bug.
Add --format option

Let the user specify different output formats. Available options
are currently "human" and "nbt-txt"
Update README

Refer to twoolie by his full name and add a bug.
Generalize recursive operations

Add a recursive traverse_subtags function and use it to re-implement
printing in human-friendly format.
Support references to TAG_List items

Add support for referencing TAG_List items. For a TAG_List named
"list", the nth element is "list.n".
Remove unused print_tag() parameter

The verbosity parameter wasn't used by anything, so take it out
for now.
Merge branch 'devel' into temp

Resolve a few commits I accidentally made on a detached head.
Update README

Squashed the bugs relating to TAG_Lists in commit efc8c387.
Print filename

Print the name of the file opened with -i.
Add --recursive and --depth options

Let the user choose whether to print recursively or not.

This changes the behavior of norbert's output considerably.
Shuffle options around

The list of options supported is growing, so try to anticipate
future options and switch a few unintuitive short options around.

This is a backwards-incompatible change in the interface. Better
to do this sooner rather than later.
Clarify usage

Explain how tags are referenced and clarify that multiple tags can be
given on the command line.
Change behavior of -o, --output-file

Don't let presence or absence of -o change what's printed to stdout.
Format code for easy viewing

Fit all lines easily on a standard 80x24 terminal.
Separate argument parsing logic

Define a separate function for splitting an arguments into their
component parts, and replace some spaghetti code with this function.
Rename function

Rename the print_tag() function to print_subtags() and move it
closer to the other print_ functions
Refactor print formatting

Generalize how printing tags is done. Now, all you should have to
do to define a new print format is define a function to format a tag
and add it to the formatters dict.

Example:

    def format_tag_human(tag):
        ...

    formatters["human"] = format_tag_human