vfb2ufo issue workarounds

[jamesgk]

vfb2ufo, which we use to convert FontLab source files to UFO toolchain input, seems to have a few open bugs:

1. Anchors are dropped from glyphs with components but no contours.
2. Composite glyphs including uni1ABE (i.e. lmidtilde_uni1ABE, dcroat_uni1ABE, eng_uni1ABE, gbar_uni1ABE, bbar_uni1ABE, and rrthook_uni1ABE) are dropped.
3. Some glyphs are decomposed (e.g. Gbar and uni04BA).

We create temporary workarounds in the toolchain for these issues while they remain open.

[behdad]

Would we get better UFO if we run robofab inside fontlab and save the font to UFO?

[jamesgk]

That's an interesting idea. AFAIK RoboFab as-is doesn't support conversion between VFB/UFO, it just provides the same API for each (in FontLab it's just a layer around the FontLab API). So I think we would have to connect the two backends somehow to get data from FontLab -> VFB-backed RFont -> UFO-backed RFont -> UFO.

[behdad]

Right. I hadn't thought about that part.

[jamesgk]

Update: it turns out that only the first issue is actually a bug with vfb2ufo -- the others were due to myself using different source VFBs on two different machines. However, the current VFBs, UFOs, and exported anchors are now all consistent within the GitHub repository (as of cd65ee5).

So since this issue is now basically a duplicate of #4, I'm opting to close it.