Avoid renaming to `new_internal`

[vaartis]

button=Gtk::Entry.new

Error in ./efinder.cr:8: wrong number of arguments for 'Gtk::Entry#initialize' (given 0, expected 1)
Overloads are:
 - Gtk::Entry#initialize(gtk_entry)

entry=Gtk::Entry.new()

But where can i find gtk_entry?

[jhass]

The above commit should make your code work.

I renamed new to new_internal in order to avoid clashes with the actually internal constructor of the wrapper taking the underlying struct. The above avoids doing that when there are no arguments, so the two constructors overload. With the next Crystal version instance variables will need mandatory type annotations, so the wrapper might need some redesign, in any case overloading the constructor should then become possible in any case and I'll tackle this issue in full then.

[vaartis]

Yep, works fine now