Unify MatchOptions new() and default() function

[kangalio]

As per its documentation, MatchOptions' default values are these:

MatchOptions {
    case_sensitive: true,
    require_literal_separator: false,
    require_literal_leading_dot: false
}

However, its derived Default implementation gives this:

MatchOptions {
    case_sensitive: false,
    require_literal_separator: false,
    require_literal_leading_dot: false
}

This Default implementation doesn't do what it should, which is potentially very confusing. Fixing this is a breaking change though, so it should wait for 0.4

[KodrAus]

Ah that is very unfortunate ☹️ In the meantime we should note in the documentation that the behavior of Default is not the same.