Destroy trace buffer upon termination

Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
updated .gitignore files for testbuild, removed obsolete flex declarations from graprof.c
tweaked top level workflow in graprof.c
Merge pull request #8 from stefanbeller/destroybuffer

Destroy trace buffer upon termination
merged changes to master into develop
added autogen.sh to generate configure script from configure.ac, mentioned this in the README
Create required folders for autoreconf and improve error message

Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
Add more things to .gitignore

Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>