Support reuse-style of dep5

[pombredanne]

There are some peculiarities in the format (usage of ** for files) and files are named dep5

[pombredanne]

@mxmehl is this true that you support special non Debian standard patterns such as "**" in REUSE's dep5 format ?
Like in https://github.com/rizinorg/rizin/blob/6f40dfe493f0caf9e0541e1ee83e3d8012b5750f/.reuse/dep5#L10 ?

[mxmehl]

In this case, we do not modify the DEP5 standard. Please find our the dep5 part in our spec.

Actually, DEP5 does not seem to support **, and it's not necessary:

Patterns match pathnames that start at the root of the source tree. Thus, Makefile.in matches only the file at the root of the tree, but */Makefile.in matches at any depth.
(source)

However, the python-debian library seems to understand it.

[pombredanne]

we do not modify the DEP5 standard.

Thank you..., that's what I thought!

However, the python-debian library seems to understand it.

let me check if this exists and how frequent this could be in the whole debian and ubuntu archive as I am trying to get the parsing working in most common cases.