Added concurrent tests to MasterInfo
Merge pull request #203 from pfxuan/master

Improve issue TACHYON-90 (JIRA): use FQDN as hostname in BlockInfo
When the master client fails to connect, it should stop trying

With the current implementation, users will end up continuously
retrying to connect to the master, because of the while loop in
each MasterClient method like

```
while (!mIsShutdown) {
      connect();
      ...
}
```

Instead of returning a boolean, we will now interrupt the control
flow during exceptional conditions, as this will should allow current
users of this API to handle it (rather than having to change every
usage of `connect()` to include a check that throws a less-helpful
error message).

Note that this does require a breaking API change, as we have added
checked exceptions to several public APIs. Since these APIs actually
do incur IO, it seems reasonable that they might throw IOExceptions,
however. The alternative would be to wrap our IOExceptions in
RuntimeExceptions, but this isn't exactly the "Java Way".
Stop the heartbeat thread.
Slight refactor of the check-for-shutdown logic
Call setConf() in TFS to ensure correct Configuration is used
Merge pull request #204 from aarondav/client-fail

When the master client fails to connect, it should stop trying
fix potential deadlock in master client
Only add S3 keys to UFS conf if not already present

Otherwise System properties will unintuitively replace keys
that were manually configured in the Conf.
Remove unnecessary final
Merge pull request #205 from aarondav/s3n

Minor improvements to UFS conf targeted at S3 usability
show tb and pb
Merge pull request #192 from manugoyal/master-info-concurrent-tests

Added concurrent tests to MasterInfo
update homepage
tweak homepage
tweak documents
update document
add comments and unit tests to TachyonFS.get()
add utils addleadingzero with unit tests
add unit tests for mkdir. add more comments