#8 Word-wrap slowness while loading and/or pasting

[Flávio Etrusco]

Fix the slowness for loading files and for pasting large amounts of lines while word-wrap is enabled (these are arguably caused by bad implementation in TSynEdit.SetSelTextPrimitive and TSynEditStringList.LoadFromStream, and can be reasonably mitigated by toggling the WordWrap property during the execution of the operation)