- always use `-Wextra` compilation flag; it was already used in CI
- always compile `ndpiSimpleIntegration` when building examples
- don't mess with optimization flags: `CFLAGS` default value is "-g -O2"
and the user can change it
Try to test -O1,2,3,s flags in CI.
Fix some warnings.
Initial work to support out-of-tree builds
```
./autogen.sh
mkdir build
cd build
../configure
make
make check
```
IMPORTANT: `autogen.sh` doesn't call `configure` automatically anymore!!
You have to do: `./autogen.sh && ./configure --$OPTIONS`.
A little bit annoying but the pattern `autogen && configure && make` is
very common on Linux.
Known issues:
* `make doc` doesn't work in out-of-tree builds, yet
* Windows/MinGW/DPDK (out-of-tree) builds have not been tested, so it is unlikely they work
See: #2992
Right now the CI takes ~30 minutes; the goal is to have it ending in
< 15 min.
The basic trick is to run the longer jobs (no_x86_64 and masan) only
with the recently updated pcaps. The same jobs will run again on schedule
(every night) testing all the traces.
This way the CI will be "green" (hopefully!) earlier while pushing new
commit/PR; full tests are simply delayed.
Details: when `NDPI_TEST_ONLY_RECENTLY_UPDATED_PCAPS` is set,
`tests/do.sh` checks only the latest 10 pcaps (i.e. the more recent pcap
added/updated) for *every* configuration.
Notes that no_x86_64 and masan jobs run twice: when pushing/merging and
on schedule (every night)
