Fix issue #349
Merge pull request #396 from gintenlabo/fix-test

Fix issue #349
Use PREFIX environment varialbe to specify install directory: fixes #355
Write installation method of jenerator
Remove catch clause which is never executed
pid_t could be possibly not int
Refactor get_machine_status
Fix deadlock on linear_mixer::stop()
Remove volatile
Refactor linear_mixer::mixer_loop
Merge pull request #406 from gintenlabo/fix-uninitialized-values

Fix issue #377 (get_status returns uninitialized values on some platform)
Merge pull request #407 from gintenlabo/remove-volatile

Remove volatile (fix issue #394)
Merge pull request #404 from unnonouno/feature/jenerator-install-path

Feature/jenerator install path
Check whether 'mecab.h' exists before version check: fix #408