game_tree. Add XML to bin game tree converter.

Just basic argument parsing, and opening the XML file for parsing.
game_tree. Initial XML game tree parsing.

Add classes for each of the basic nodes in the tree.
Read the XML file.
Parse each of the basic XML nodes, and create a python objet for each.
game_tree. Rename render object to render geometry
game_tree. Add string representation to all tree nodes.
game_tree. Change root string reprentation to specify it's the root object.

Add object utility method to create string representation of object content.
game_tree. Add parsing of game information.

Add game, renderer and render pass node parsing.
Change parsing of other nodes to pass the game node for global testing of parsing.
Merge branch 'master' into game_tree
game_tree. Encode the game tree to binary format.

Data value encoding not implemented.
Add binary encoding for all other XML game tree nodes.
Add encoding constant for each node type.
Add dump of binary tree to a binary file.
game_tree. Use utility functions to write data to binary file.

Add a utility function to write unsigned int, char and string to binary file.
Change write implementation for all nodes to use utility functions.
game_tree. Rename write encoding to write prefix.
game_tree. Change data name/value to generic name/value nodes.

Change data name and data value nodes to generic name and value nodes for any other nodes in the tree.
Change how game name is stored in the tree, from the text of the game node, to a name node.
game_tree. Change how render passes are stored in the renderer.

Change render pass container in the renderer to a dictionary - pass_name : pass_index.
Render passes are still serialized in the order they appear in the XML tree.
game_tree. Change to how the render pass is stored in a render function.

Hold the render pass as an unsigned integer, instead of as a string.
game_tree. Add writing render pass type.
game_tree. Rename write constant to write string constant.
game_tree. Change object writing to use 2 char constants.

Change all game node constants to have a unified format.
Object constants start with an o
Audio constants start with an a
Render constants start with an r
Render pass constants start with a p
Resource constants start with an f
game_tree. Fix an object writing.

Write object end token.
Change Root object start token to root object constant.
game_tree. Change to child content writing.

Only write renders, audio source, data, and children if their number is greater than 0.
game_tree. Add end tokens to renderer, render and audio source.
game_tree. Change audio source writing.

Write a token to mark start of audio source buffers.