Updates Powered by Mesos list to include MediaCrossing and Xogito.
Updates Mesos Roadmap to point to JIRA.
Removes out of date Hadoop on Mesos documentation from 2011.
Removes previously revised date, and updates information regarding downloading the latest release.
Fixed build breakage from 37e946683f1bb6a.

In 37e946683f1bb6a I fixed a build failure from a warning, which are
treated as errors.

Newer versions of GCC have a feature (documented here:
http://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html) where unknown
warning flags are ignored.

In older version of GCC (such as 4.1 or 4.2), it appears that these flags
aren't ignored, resulting in an error.

Review: https://reviews.apache.org/r/14164
Check for automake 1.14 in bootstrap.

Review: https://reviews.apache.org/r/14183
Updated CHANGELOG and docs for 0.14.0.