Change MinGW build settings when building shared library type.

- Statically link standard C runtime libraries.
- Does not use 'lib' prefix.

All credits to alexrass (See http://urho3d.prophpbb.com/topic46.html and http://urho3d.prophpbb.com/topic90.html).
Partially reverted the AnimatedModel LOD determination change: use the animated bounding box center to calculate distance from camera. This is to ensure ragdolls will LOD correctly even if their bones move far from the root node.
Added FileChanged event sent by ResourceCache for manually responding to changed files in resource directories.
Removed debug print from editor.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	Source/Engine/Graphics/AnimatedModel.cpp
	Source/Engine/Resource/ResourceCache.cpp