[TCLCORE] FRQ 3010352: Simplifying Stubs for TclOO

[Jan N. <jan...@gm...>]

Hi all,

Various discussions have been held about the Stubs
mechanism being too complicated, here is a tiny
step in the right direction (I believe)

One of the difficulties is the need for -DUSE_XXX_STUBS
when compiling extensions against the exported
API for some extensions XXX. FRQ 3010352 is
about eliminating the need for -DUSE_TCLOO_STUBS
for TclOO, but the same could be done as well for
tdbc and Itcl.

A second advantage of the approach is that all
related symbols become MODULE_SCOPE, which
means that Stubs form the only mechanism that
those symbols can be accessed. Less exported
symbols mean faster loading, and it doesn't
cost anything: Stubs are the only supported
way to access the TclOO API, although it
is not enforced up to now. This change
enforces it.

Now a "freq-3010352-impl" branch is
created demonstrating this for TclOO.
ttk and tkImg already implement this
(yes, I eat my own dogfood...),
TclOO would be the logical next candidate
showing this to the world.

Remarks more than welcome!

Regards,
          Jan Nijtmans