MAINT: _lib: add __dealloc__ to MessageStream
MAINT: _lib: add __dealloc__ to MessageStream

Extension class `MessageStream` doesn't implement a `__dealloc__` method which is required to free C level structures once the object goes out of scope. It is possible to do so with a call to the `close()` method but it is very inconvenient to call it every time one doesn't need the message stream anymore. Also, there could be a memory leak if one forgot to call the `close` method. Using `__dealloc__`, we can tell Cython to manage memory automatically for us.
zerothi/scipy,matthew-brett/scipy,scipy/scipy,Eric89GXL/scipy,rgommers/scipy,endolith/scipy,perimosocordiae/scipy,Stefan-Endres/scipy,andyfaff/scipy,tylerjereddy/scipy,tylerjereddy/scipy,rgommers/scipy,mdhaber/scipy,WarrenWeckesser/scipy,zerothi/scipy,grlee77/scipy,andyfaff/scipy,vigna/scipy,ilayn/scipy,ilayn/scipy,Eric89GXL/scipy,Eric89GXL/scipy,zerothi/scipy,endolith/scipy,grlee77/scipy,andyfaff/scipy,Eric89GXL/scipy,Eric89GXL/scipy,anntzer/scipy,ilayn/scipy,matthew-brett/scipy,ilayn/scipy,matthew-brett/scipy,anntzer/scipy,zerothi/scipy,rgommers/scipy,tylerjereddy/scipy,Eric89GXL/scipy,grlee77/scipy,perimosocordiae/scipy,zerothi/scipy,andyfaff/scipy,scipy/scipy,perimosocordiae/scipy,grlee77/scipy,WarrenWeckesser/scipy,grlee77/scipy,perimosocordiae/scipy,endolith/scipy,WarrenWeckesser/scipy,mdhaber/scipy,WarrenWeckesser/scipy,mdhaber/scipy,scipy/scipy,andyfaff/scipy,rgommers/scipy,anntzer/scipy,Stefan-Endres/scipy,tylerjereddy/scipy,WarrenWeckesser/scipy,Stefan-Endres/scipy,anntzer/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,anntzer/scipy,tylerjereddy/scipy,vigna/scipy,rgommers/scipy,perimosocordiae/scipy,Stefan-Endres/scipy,scipy/scipy,vigna/scipy,Stefan-Endres/scipy,vigna/scipy,endolith/scipy,mdhaber/scipy,mdhaber/scipy,matthew-brett/scipy,anntzer/scipy,vigna/scipy,ilayn/scipy,ilayn/scipy,andyfaff/scipy,mdhaber/scipy,scipy/scipy,matthew-brett/scipy,endolith/scipy,perimosocordiae/scipy,zerothi/scipy,scipy/scipy,endolith/scipy