Fix warning that NSEC_PER_SEC is defined on OS X
Compile error on OS X - missing bracket
Improve wording of AC_DEFINEs in configure.ac
Use AS_CASE instead of case/esac
Use tabs instead of whitespaces in configure.ac

Additionally, do not use line breaks in AS_HELP_STRING, AC_MSG_ERROR, or
AC_MSG_WARN macros since m4 cannot handle trailing whitespace properly.
Clock_gettime implementation for OS X

OS X does not have clock_gettime, use clock_get_time instead.
Non-recursive automake

According www.flameeyes.eu/autotools-mythbuster/automake/nonrecursive.html
non-recursive make files have several advantages over the recursive
'classic' version. One advantage is that it exists only a single Makefile.am
to edit, and a single Makefile.in to be processed during ./configure
mrproper make target

Pre-existing make *clean targets are not suitable to delete all generated
files by 'autoreconf -i'. mrproper will clean up all those files.
Require at least automake v1.10
Update travis.linux.install.deps.sh
Merge pull request #121 from alexander-zimmermann/next

Autotools stuff & OS X support
Added checks to ensure provided directory for dump files is valid and correctly formatted, defaults to CWD if not provided
fixed possible crash in case dump thread is canceled and cleanup function is called twice
fixed possible crash in case dump thread is canceled and remove_flow() is called before dump thread actually terminated
fixed that uninit_flow() invalidates all existing pointers to flows following the one in question
dummy