Handle indentation

[medrimonia]

Some standards should be chosen, there's mainly three questions

• Use a specific indentation for each language or one for all ?
• Tabs or space ?
• Indent size, 2, 4 or 8 ?

I think that for all our files, spaces should be preferred to tabs. But for nethack patches, we should match nethack indentation.

[medrimonia]

Indentation mode has been chosen :

• Tabs are used for indentation
• Spaces are used for alignment

Example :

...
<tab>function_call(arg1
<tab><   spaces   >arg2
<tab><   spaces   >arg3);
...

Indentation has been done on this model on some files, everyone can check on it's own and correct it now