Fix the bug mentioned in [TACHYON-66]

Fix the bug mentioned in [TACHYON-66] "The memory usage statistics is
not right when multi-user cache the same file and stops their
connection".
Change the synchronized range
return immutable copy of children to avoid concurrent read and write
format
added BasicNonByteBufferOperations into runTests
refactored runTests to be a for loop
[TACHYON-82] Retrieving byte buffer from remote machine can leak file handles in TachyonFile
Merge branch 'master' of https://github.com/mubarak/tachyon into TACHYON-82

Conflicts:
	core/src/main/java/tachyon/client/TachyonFile.java
Fixing merge issue
Fixing RemoteBlockInStream.java
Merge pull request #364 from dcapwell/concurrency-issue-masterinfo-getFilesInfo

return immutable copy of children to avoid concurrent read and write
[TACHYON-82] Retrieving byte buffer from remote machine can leak file handles in TachyonFile. Fixing code review comments.
validate data in example
made a few classes implement closeable
Merge pull request #365 from dcapwell/example-in-runTest

Example in run test
Merge pull request #366 from mubarak/TACHYON-82

[TACHYON-82] Retrieving byte buffer from remote machine can leak file handles in TachyonFile
Add a unit test for cacheBlock

Add a unit test for cacheBlock
Merge pull request #370 from dcapwell/implement-closable

made a few classes implement closeable
stop can target a component
Merge remote-tracking branch 'upstream/master' into TACHYON-66