Glob(): add an include_hidden flag

[mwichmann]

Glob inherits from Python's glob.glob special handling of directory entries that begin with dot. This rule is, in turn, inherited from POSIX (UNIX) glob, which refers to this piece from section 2.13.3 on filename expansion:

2.If a filename begins with a <period> ('.'), the <period> shall be explicitly matched by using a <period> as the first character of the pattern or immediately following a <slash> character. The leading <period> shall not be matched by the <asterisk> or <question-mark> special characters, a bracket expression containing a non-matching list, such as "[!a]", a range expression, such as "[%−0]", or a character class expression, such as "[[:punct:]]".

In very recent Python (will be in the 3.11 release next month), there is a new flag include_hidden which turns off this special behavior and allows a leading dot to be matched.

Propose that we extend Glob with a keyword argument of the same functionality (could be the same name or different)