Merge branch 'release/0.4.2'
clarify that type of values in num_values are float
add link to homebrew tap repository
fix wrong product name
fix typo in API references
Update glog and pficommon requirements for building: fixes #39
Fix FAQ sasys buliding requirement Python version: refs #40

Current waf unittest_gtest included in Jubatus 0.4.2 and below,
that doesn't support Python 2.4 but supports 2.5 and later.
fix Japanese expression in common_structs.rst
Merge branch 'master' into develop
change version required to build jubatus