Add experimental Travis setup
correct add-apt-repository
simplify scripts, add badge
Make build verbose
add test script
Merge branch 'travis'
Sync CHANGES
travis: install native compilers
sync oasis autogen
install time package in Travis
improve the Travis test matrix with the latest PPAs
Check and raise error in case of negative offsets for blits

Closes #4
travis: install time
a candidate fix for mirage/ocaml-cstruct#3
better fix for mirage/ocaml-cstruct#4 so that parsing outputs the right integer literals
test: fix enum test compilation
tests: restore pcap printing
tests: make basic test compile again with new api
sync CHANGES
Correctly preserve the sequence after a constant constructor is set during a `cenum` definition.

closes #10