* Add a null terminator to loaded TinyXML files
The TinyXML parse() function expect a C-like string, including terminator.
When xml loading was changed, it loaded the file, but included no such thing.
Thus, we load the file, then reallocate the memory so that we can insert a
null terminator to it, before passing it to parse().
* Tweak TinyXML file loading
Instead of first loading the file content into memory, then reallocate it
to add a null pointer, add an argument to the file load function for whether
to append a null terminator or not, defaulting to false. It still returns the
length without the null pointer in case a length ptr is passed.