Merge remote-tracking branch 'github/master'

# Please enter the commit message for your changes. Lines starting
# with '#' will be ignored, and an empty message aborts the commit.
# On branch master
# Your branch is ahead of 'baidu/master' by 3 commits.
#   (use "git push" to publish your local commits)
#
# Changes to be committed:
#	new file:   .gitignore
#	new file:   LICENSE
#	new file:   README.md
#
# Untracked files:
#	pt-timer.h
#
