driver/ppm_events_public: change ppm_param_info.symbols in info.

Change ppm_name_value* symbols in void* info, so that we can store
extra informations for parameters which can have multiple
meanings/types depending on some other parameters.
driver: add PPME_SYSCALL_PTRACE_*
driver: handle request parameter of ptrace syscall
driver/ppm_fillers: add simple ptrace_x filler
start converting ptrace "addr" param to PT_DYN
driver: prepare fillers and val_to_ring to accept dyn_idx

TODO: implement PT_DYN type
implement PT_DYN in both driver and userspace
implement ptrace filler and parse some requests
driver/ppm_fillers: refactor ptrace_x filler
userspace/libsinsp/event: fix error when handling PT_DYN params
Merge branch 'master' into ptrace_filler2

Conflicts:
	userspace/libsinsp/event.cpp
minor fixes to the help text
zsh completion: more correctly omitting closing -p quote

If I have

$ sysdig -p '%fd.si

and I press TAB, I do not want

$ sysdig -p '%fd.sip'

Note the trailing '

This patch fixes this. Previously I switched to _describe from _alternative to
get this behavior, but that doesn't actually work (why did I think it did?).
We're now good except some pieces of the code use _describe and others use
_alternative. Would be good to be consistent, but it really doesn't matter
zsh completion: added new options in 0.1.85
bash completion: added new options in 0.1.85
Merge pull request #204 from dkogan/master

Tab completion updates
Try to install zsh completion under site-functions as well because Fedora uses that non-standard path as default
typo
When CMAKE_BUILD_TYPE is not specified, default to Release
test commit on sysdig