Bugfix/feature release for dropwatch
- Support packet drop reason reporting when included in netlink message
- fix some minor compilation warnings/errors
- clean up some comments about deadline support
- convert configure.ac to use AM_PROG_LIBTOOL from outdated LT_INIT
- Fix missing SOL_NETLINK define in glibc < 2.24
- Fix licensing issues that didn't make sense
- ignore ENOBUFS errors on data socket
- adding arm64 travis ci testing
- man page updates
- move to libnl3 from libnl