lazychaser#96: don't fill children when rebuilding tree

Allow l5.3

Merge pull request lazychaser#119 from oddvalue/patch-1

Start new nested set query in fixTree

Fixed lazychaser#103: descendants now restored

Added some assertions

Fixed lazychaser#93: works with prefixed tables

Fixed lazychaser#91: removed param type from event callbacks since fa…

…iling in php 7

Refactored tree flattening

lazychaser#50: implemented tree rebuilding feature

Fixed descendants issue