[Java] Make sure alignment and memory padding conform to spec

[asfimport]

Per spec 8 byte alignment and padding for buffers.

Reporter: Micah Kornfield / @emkornfield

PRs and other links:

• GitHub Pull Request apache/arrow#98

_{Note: This issue was originally created as ARROW-186. Please see the migration documentation for further details.}

[asfimport]

gaurav agarwal:
We need to do this while allocating memory thrugh ByteBuffer and Allocation Mangaer in memory packge of Arrow

[asfimport]

Kirils Mensikovs:
Hi, I added 64-byte memory check apache/arrow#98

[asfimport]

Wes McKinney / @wesm:
@xhochy @julienledem I don't think this should block the release – do you agree?

[asfimport]

Uwe Korn / @xhochy:
+1 for not making this a blocker

[asfimport]

Julien Le Dem / @julienledem:
yes agreed, this is not a blocker.

[asfimport]

Neal Richardson / @nealrichardson:
Is this issue still valid?

[asfimport]

Micah Kornfield / @emkornfield:
The spec has changed.  I believe Java does to 8-byte alignment, but would need to double check.