Template antioch_version for basic_ostream usage

Reworks antioch_version_stdout to delegate to antioch_version.  New
antioch_version accepts any templated basic_ostream you like, avoids
repeatedly flushing the stream via std::endl, and returns the stream for
later use.

Result is, caveat build time, identical on my system.

Desirable as dumping version information to a ostringstream can be handy
at times.
Merge pull request #31 from RhysU/version_ostream

Template antioch_version for basic_ostream usage
Get test-suite.log from the right directory
Add Travis-CI build status image
Testing VexCL interoperation on Travis-CI

Also make travis badge link to the project page on travis-ci.org
Merge pull request #32 from ddemidov/travis-vexcl

Testing VexCL interoperation on Travis-CI