Remove hunspell dependency

[danielnaber]

To provide a 100% pure Java software, we'd like to switch from Hunspell native code to Morfologik. See http://wiki.languagetool.org/hunspell-support for how to build the Morfologik dictionaries.

Find all affected languages by looking for usages of Hunspell and its sub classes (like HunspellNoSuggestionRule):

• Asturian
• Spanish
• Tagalog
• Esperanto (@dpelle will try to switch this one)

The following might not be trivial to port to Morfologik:

• Icelandic (first try ended in words like virkar and texta not being recognized by Morfologik, but they are accepted by our hunspell code...)
• Galician (looks like unmunch doesn't work well with this .aff, it returns things like construíu/102,103,104| -- seems to be caused by "recursive" definitions like SFX 232 oñer ón/104 poñer)
• Khmer (tricky for me because of the characters and tokenizing, see local branch)
• Danish - requires compound support, also uses ^ and _ in its REP statements, not supported by replacement-pairs in Morfologik yet
• French - uses ^ and $ in its REP statements, not supported by replacement-pairs in Morfologik yet (see https://github.com/morfologik/morfologik-stemming/issues/38)
• German - requires compound support
• Swedish - requires compound support
• Portuguese - pt_BR has 394 REP statements, which might slow down Morfologik too much

[danielnaber]

Also see the discussion at http://www.mail-archive.com/languagetool-devel@lists.sourceforge.net/msg04435.html

[danielnaber]

For the recursive tags, Laszlo suggests to use the output of the first unmunch as a dictionary for a second unmunch. I couldn't make that work yet in a sensible way (tried with Galician).

[ghost]

Compound support would be needed for a lot of languages. The + side is it accepts words just invented; the - side is it also accpets some wrong words that are technically correct. For all those languages using a huge words list and hunspell dictionary as a filter will render a workable words list. I guess 99.99% coverage would be good enough. With a large corpus as input, it can be done.