Merge pull request #6 from jedisct1/assert-fix

Fix buggy assertion triggered when sendto() runs out of output buffers
Merge pull request #7 from jedisct1/reuseport

Use SO_REUSEPORT on Linux, if supported.
Merge pull request #8 from jedisct1/doc-nits

Documentation nits
Merge pull request #9 from jedisct1/IP_PMTUDISC_OMIT

Use IP_PMTUDISC_OMIT instead of IP_DONTFRAG if supported
support OpenBSD #10
fix typo
better
Delete README.cn.md
Update README.md
Update README.md
Update README.md
mark HEAD as 0.1.12
workaround clang not system wide, fail on sudo make install