Now faceposing tools should be able to set case sensitive flexes for child entities.

Disabled line multiselection in menus to avoid confusion.

Now the slider used for angles ranges from -180 to 180

- Added a simple PAC3-style editor that allows to change position, angle and scale of child entities
- Now the tool's menus don't lock the screen when they're open. Instead, you can access them from the context menu, while holding C
- Fixed a memory leak
- Now child entities preserve their color and submaterials on NPC death

Child models disappear faster on NPC death.

Fixes related to child bones manipulation