Fix conversion of ctypes pointers passed to C extension

[Araneidae]

As reported in issue #153 there appears to be a problem in converting a Python integer generated by ctypes.address() back to a void* pointer when naively using PyArg_ParseTuple.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 87.73%. Comparing base (f2330b6) to head (d55483d).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #154 +/- ## ======================================= Coverage 87.73% 87.73% ======================================= Files 14 14 Lines 1019 1019 ======================================= Hits 894 894 Misses 125 125 ```

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Unit Test Results

     15 files  ±0       15 suites  ±0   27m 43s :stopwatch: -19s    278 tests ±0     262 :heavy_check_mark: ±0    16 :zzz: ±0  0 :x: ±0  4 170 runs  ±0  3 575 :heavy_check_mark: ±0  595 :zzz: ±0  0 :x: ±0 

Results for commit 57790d47. ± Comparison against base commit f2330b64.