fix os.matchnext for entries starting with a dot

[IreNox]

fixed the problem that os.matchfiles and os.matchdirs doesn't return files and dirs starting with a dot.

[rhoot]

I'd rather see it as an opt-in option. More often than not you don't want to include them. E.g, .git, .hg, .DS_Store, various cache folders, etc. It also matches the behavior of other APIs/programs. ls doesn't show them by default, glob doesn't include them by default, bash doesn't match them against *, only .*.

Premake 5 took the same approach as bash: os.matchfiles("*") doesn't match dot files, os.matchfiles(".*") matches only dot files. Maybe we should too, so if you want both you have to do os.matchfiles("*", ".*").

[IreNox]

I switched back to Premake.