ARROW-1224: [Format] Clarify language around buffer padding and align…
ARROW-1224: [Format] Clarify language around buffer padding and align…

Added some clarifications on memory layout w.r.t padding and alignment.

Author: siddharth <siddharth@dremio.com>

Closes #932 from siddharthteotia/ARROW-1224 and squashes the following commits:

dd5f2214 [siddharth] ARROW-1224: [Format] Clarify language around buffer padding and alignment in IPC

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