Fix import paths & wrap traces in an if block

[ACrazyTown]

This PR changes the source/import path of hxCodec so that its source files can be imported like an actual library, instead of being accessible from the root.

Additionally it also wraps some traces into an if block for the conditional HXC_DEBUG_TRACE

Import examples: OLD:

import VideoHandler;

NEW:

import hxcodec.VideoHandler;

Tested and works on Windows 10, unsure about other targets.