Parser Preview

Preview release of new parser. Do not use this outside of test server (or at least take backups). This is so I can see what is broken and get someone else do a bit debugging - I don't have enough time to do all that myself.

• Added multithreaded parser
• Loading scripts now freezes server for shorter time than before
• Added gliding events and expression
• Added area effect cloud support (experimental)
• Added inventory open/close events (closes #217)
• Added expression for gravity (NoGravity flag of Vanilla)
• Added effect to force player respawn (no NMS)
• Fixed timings not working on Windows (closes #211)
• Fixed encoding issue with documentation (now uses UTF-8 always)

Probably broken stuff, especially:

• Parser logging, mostly
• Error reporting might be more confusing too (due to bugs)
• Some of new expressions/whatever added are tested too little

Please report (at least) the following:

• If some addon that worked with previous version doesn't work now
• If something else that previously worked doesn't work now
• If the logging is confusing and you have some idea how to fix it
• If this doesn't work on 1.9 properly, tested mostly on 1.10

So, I'll leave it here. Please report the bugs. Then this might be at least somewhat functional by the time when 1.11 hits.