+и<subst>

I have been investigating on the substantivisation suffix и. It was not very clear.

As your quote Luutonen in #5, it is very close to the third person affix (and, I guess, maybe comes from it), but there are differences with it.

* There is no ӗ in any form. It is always и.
* The duplication rules are different: as for px3sg, there is duplication for words that end in ӑ or ӗ, if preceded only by a consonant (ҫурӑ > ҫурри, but тутлӑ > тутли); but also adjectives finishing in consonant have duplication (пысӑк > пысӑкки, пӗчӗк > пӗчӗкки, аван > аванни).
* The oblique forms are almost always the ones that come after px3sg, but not for genitive (`лайӑх+и : лайӑххин`, cf. `информаци : информацийӗн`)
* This affix cannot be added to adjectives ending in и, у, or ӳ (I have created an A2-IUÜ paradigm for them).

So:

* Whether I continue to put {и} in the definition of this suffix in twol, it should be another archiphoneme (not the one for px3sg).
* I added `{ː}` to all adjectives finishing in `VC[ӑӗ]` (as it is done for nouns), and it seems to work
* Unfortunately we cannot add `{ː}` to all adjectives finishing by one single consonant. I tried it, but the problem is that duplication now happens with other suffixes, for instance +ах. There is duplication only for +и (it seems).

Tests can be found in ([и_subst.yaml](https://github.com/apertium/apertium-chv/blob/master/tests/%D0%B8_subst.yaml)). The results bellow are from a test with лайӑх defined as `лайӑх:лайӑх%{ː%} A2;` (but пысӑк, пӗчӗк and аван defined without `{ː}`). Notice how the test passes for лайӑх+и, for instance, but not for `лайӑх+ах`, while for аван (defined without {ː}), the situation is the opposite.

```
$ aq-morftest и_subst.yaml | more
--------------------------------------
Test 0: и (Lexical/Generation)
--------------------------------------
[PASS] лайӑх+и => лайӑххи
[FAIL] пысӑк+и => missing results: пысӑкки
[FAIL] пысӑк+и => unexpected results: пысӑкӗ
[FAIL] пӗчӗк+и => missing results: пӗчӗкки
[FAIL] пӗчӗк+и => unexpected results: пӗчӗкӗ
[FAIL] аван+и => missing results: аванни
[FAIL] аван+и => unexpected results: аванӗ
[PASS] тутлӑ+и => тутли
[PASS] ҫурӑ+и => ҫурри
[PASS] хура+и => хури
[PASS] хитре+и => хитри
[FAIL] лайӑх+и => missing results: лайӑххин
[FAIL] лайӑх+и => unexpected results: лайӑххине
[PASS] лайӑх+и => лайӑххипе
[PASS] лайӑх+и => лайӑххисем
[PASS] лайӑх+и => лайӑххисен
[FAIL] лайӑх+ах => missing results: лайӑхах
[FAIL] лайӑх+ах => unexpected results: лайӑххах
[PASS] лайӑх => лайӑхрах
[PASS] аван+ах => аванах
[PASS] аван => авантарах
[FAIL] аван => unexpected results: аванрах
Test 0 - Passes: 11, Fails: 11, Total: 22

```

P.S.
I was in the Humanities Institute discussing it with the whole philology department. They do not agree whether it is possible or not that a possessive comes after this substantivisation suffix. If it is, it should be extremely rare, and I have not find such cases in our corpus, so I removed the possibility to add possessives after this suffix (I put there a few days ago: now it is like it was).