Find appropriate settings for recursion_limit, stack size

[tcr]

Stack size is important (see the parse function in root) to not cause stack overflows. I picked an arbitrary value here, but there might be a more scientific way of picking one or even figuring out why the code needs a stack size increase.

recursion_limit might not be needed to be set at all. Should be tested against the test bench.

[tcr]

Can be closed after #27

[birkenfeld]

Done!