Unify MatchOptions new() and default() function

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

Locate the MatchOptions implementation and compare the behavior of its new() and default() functions with the documented values. Update the default behavior so case_sensitive matches the documented default, then verify the public API behavior and account for the planned 0.4 breaking change.