Fixing #2095 - Crash with enchant 2.x

Issue: Client crashes when loading Enchant 2.x

There are a few compounding problems that caused this:

• We were loading the unversioned soname
• There was no error handling on failure
• Enchant broke ABI

So the solution was just to avoid unversioned sonames, when something goes wrong log it and don't explode, and have fallbacks for the new ABI: https://github.com/hexchat/hexchat/commit/005858795878b92fc17b4c2127bce90a1d053483

Fixing the current problem and making it more robust in the future.