[FLUME-2215] ResettableFileInputStream can't support ucs-4 character.

Patch by Alexandre Dutra:
https://issues.apache.org/jira/secure/attachment/12620855/FLUME-2215-1.patch
Ensure proper file permissions on TestHDFSEventSinkOnMiniCluster.

MiniDFSCluster will fail if DFS_DIR has permissions other than
rwxr-x-r-x. This is usually accomplished by having umask set to
0022, which is unconvenient for testing. So we try to set such
permissions with setfacl.
Add Travis CI conf.
Fix TestResettableInputStreamReader.
Adapt TestResettableInputStreamReader to Java 8.
[FLUME-2483] Ignore TestLog.doTestMinimumRequiredSpaceTooSmallForPut.
Update apache parent pom to version 15.
travis: Raise ulimit for new threads.

Solves Travis CI exception on oraclejdk7:
https://travis-ci.org/Stratio/flume/jobs/36814709#L5747
https://github.com/travis-ci/travis-ci/issues/2496
[FLUME-2203] Add jsr-305 dependency.
[FLUME-2286] Upgrade Guava to 17.0.
Upgrade snappy-java to 1.1.1.3.
travis: Make hostname point to 127.0.0.1. Fixes HBase tests.
travis: Build all Hadoop profiles.
maven: Increase memory for tests, decrease stack size.
travis: Use OpenJDK 6 too.