Improve game load delay

[tchegito]

Measured on a Galaxy S2, when user clicks on a saved game, we can wait during 7 seconds. This is too long.

Some tracks to explore:

• SAX instead of DOM parsing (less memory footprint and faster)
• parallelisation 1 thread per XML file

[tchegito]

Improved in [2.52]

Now parsing lasts only 2 seconds on Galaxy S2.

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