First stab at hayai-config.cmake setup

Attempt to provide CMake find_package config mode for hayai project.
The configuration is based on the official tutorials:
http://www.cmake.org/Wiki/CMake/Tutorials/How_to_create_a_ProjectConfig.cmake_file
http://www.cmake.org/Wiki/CMake/Tutorials/Exporting_and_Importing_Targets

TODO: move public headers to include/hayai or tweak /src in CONF_INCLUDE_DIRS
Merge pull request #4 from mloskot/hayai-config.cmake

First stab at hayai-config.cmake setup
Add Travis build file.
Link Hayai sample against librt on non-Apple UNIXes.
Remove sample from installed files, include librt on Linux as dependency.
Install Valgrind in test environment.
Add build status to README for Github niceness.
Add Mateusz Loskot to list of authors.
Merge remote-tracking branch 'nickbruun/master'