Revert 999fa571 so timeouts do not kill client.
Revert 999fa571 so timeouts do not kill client.

This reverts commit 999fa5713ac69e1617067dad7b47df6e5039115b.
Switch timeout handling to explicitly use INT_CANCEL since tdserror() converts INT_TIMEOUT to INT_CONTINUE

marshall-lee/tiny_tds,NCSAAthleticRecruiting/tiny_tds,dxw/tiny_tds,0x00evil/tiny_tds,dxw/tiny_tds,FayeFang/tiny_tds,FayeFang/tiny_tds,marshall-lee/tiny_tds,0x00evil/tiny_tds,NCSAAthleticRecruiting/tiny_tds