ARROW-617: [Format] Add additional Time metadata and comments based on discussion in ARROW-617
ARROW-617: [Format] Add additional Time metadata and comments based on discussion in ARROW-617

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

Closes #385 from wesm/ARROW-617 and squashes the following commits:

f9f0571 [Wes McKinney] Add metadata and comments based on discussion in ARROW-617

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