ARROW-817: [Python] Fix comment in date32 conversion
ARROW-817: [Python] Fix comment in date32 conversion

Author: Wes McKinney <wes.mckinney@twosigma.com>

Closes #536 from wesm/ARROW-817 and squashes the following commits:

3982948 [Wes McKinney] Fix comment

icexelloss/arrow,dremio/arrow,xhochy/arrow,majetideepak/arrow,wagavulin/arrow,wesm/arrow,tebeka/arrow,pcmoritz/arrow,siddharthteotia/arrow,xhochy/arrow,renesugar/arrow,jeffknupp/arrow,yufeldman/arrow,kou/arrow,yufeldman/arrow,wesm/arrow,NonVolatileComputing/arrow,renesugar/arrow,majetideepak/arrow,cpcloud/arrow,apache/arrow,laurentgo/arrow,jeffknupp/arrow,kou/arrow,dremio/arrow,yufeldman/arrow,majetideepak/arrow,wagavulin/arrow,tebeka/arrow,xhochy/arrow,kou/arrow,pcmoritz/arrow,siddharthteotia/arrow,pcmoritz/arrow,kou/arrow,icexelloss/arrow,apache/arrow,pcmoritz/arrow,xhochy/arrow,cpcloud/arrow,cpcloud/arrow,NonVolatileComputing/arrow,icexelloss/arrow,yufeldman/arrow,xhochy/arrow,dremio/arrow,wagavulin/arrow,apache/arrow,kou/arrow,laurentgo/arrow,jeffknupp/arrow,majetideepak/arrow,icexelloss/arrow,NonVolatileComputing/arrow,siddharthteotia/arrow,cpcloud/arrow,NonVolatileComputing/arrow,tebeka/arrow,apache/arrow,wesm/arrow,pcmoritz/arrow,apache/arrow,apache/arrow,majetideepak/arrow,kou/arrow,renesugar/arrow,icexelloss/arrow,siddharthteotia/arrow,dremio/arrow,apache/arrow,wesm/arrow,wesm/arrow,apache/arrow,majetideepak/arrow,NonVolatileComputing/arrow,NonVolatileComputing/arrow,xhochy/arrow,xhochy/arrow,kou/arrow,apache/arrow,itaiin/arrow,itaiin/arrow,majetideepak/arrow,majetideepak/arrow,wesm/arrow,renesugar/arrow,wagavulin/arrow,majetideepak/arrow,laurentgo/arrow,itaiin/arrow,majetideepak/arrow,laurentgo/arrow,siddharthteotia/arrow,majetideepak/arrow,laurentgo/arrow,wagavulin/arrow,itaiin/arrow,dremio/arrow,icexelloss/arrow,yufeldman/arrow,kou/arrow,yufeldman/arrow,renesugar/arrow,cpcloud/arrow,renesugar/arrow,laurentgo/arrow,apache/arrow,itaiin/arrow,jeffknupp/arrow,wagavulin/arrow,xhochy/arrow,majetideepak/arrow,itaiin/arrow,tebeka/arrow,wesm/arrow,jeffknupp/arrow,laurentgo/arrow,apache/arrow,dremio/arrow,wagavulin/arrow,wesm/arrow,pcmoritz/arrow,icexelloss/arrow,dremio/arrow,jeffknupp/arrow,NonVolatileComputing/arrow,xhochy/arrow,laurentgo/arrow,pcmoritz/arrow,pcmoritz/arrow,cpcloud/arrow,jeffknupp/arrow,icexelloss/arrow,dremio/arrow,wagavulin/arrow,laurentgo/arrow,renesugar/arrow,pcmoritz/arrow,tebeka/arrow,tebeka/arrow,tebeka/arrow,cpcloud/arrow,cpcloud/arrow,siddharthteotia/arrow,NonVolatileComputing/arrow,laurentgo/arrow,pcmoritz/arrow,itaiin/arrow,jeffknupp/arrow,itaiin/arrow,icexelloss/arrow,majetideepak/arrow,pcmoritz/arrow,cpcloud/arrow,siddharthteotia/arrow,itaiin/arrow,wesm/arrow,wagavulin/arrow,kou/arrow,apache/arrow,renesugar/arrow,wesm/arrow,kou/arrow,dremio/arrow,wesm/arrow,itaiin/arrow,wagavulin/arrow,dremio/arrow,yufeldman/arrow,wesm/arrow,icexelloss/arrow,laurentgo/arrow,laurentgo/arrow,siddharthteotia/arrow,laurentgo/arrow,cpcloud/arrow,icexelloss/arrow,wesm/arrow,apache/arrow,cpcloud/arrow,icexelloss/arrow,xhochy/arrow,apache/arrow,yufeldman/arrow,kou/arrow,xhochy/arrow,xhochy/arrow,wagavulin/arrow,tebeka/arrow,majetideepak/arrow,itaiin/arrow,renesugar/arrow,xhochy/arrow,yufeldman/arrow,pcmoritz/arrow,cpcloud/arrow,renesugar/arrow,jeffknupp/arrow,itaiin/arrow,wesm/arrow,cpcloud/arrow,renesugar/arrow,itaiin/arrow,pcmoritz/arrow,tebeka/arrow,xhochy/arrow,icexelloss/arrow,NonVolatileComputing/arrow,kou/arrow,siddharthteotia/arrow,renesugar/arrow,laurentgo/arrow,kou/arrow,pcmoritz/arrow,itaiin/arrow,NonVolatileComputing/arrow,renesugar/arrow,yufeldman/arrow,dremio/arrow,xhochy/arrow,siddharthteotia/arrow,renesugar/arrow,jeffknupp/arrow,itaiin/arrow,yufeldman/arrow,NonVolatileComputing/arrow,siddharthteotia/arrow,icexelloss/arrow,jeffknupp/arrow,majetideepak/arrow,renesugar/arrow,pcmoritz/arrow,kou/arrow,wagavulin/arrow,tebeka/arrow,cpcloud/arrow,laurentgo/arrow