wldbg: add error flag

passes can set this flag to indicate that an error happend
and the epoll loop should break with an error.
list: close dir after using

don't leak
list: fix printing

print which passes are hardcoded and do not continue in
running wldbg after printing is done
wldbg: add verbose mode to debug

use vdbg for verbose debug and dbg for normal debug

WLDBG_DEBUG=verbose or WLDBG_DEBUG=v will trun the verbose mode
wldbg: add verbose debug messages

print when writing to and flushing a connection in verbose mode
(needed it while debugin smthing)
wldbg: set sigaction.sa_flags to zero

Fixes compiler warning
wldbg: do not continue in main after an error

When some pass indicated error, do not continue in main
interactive: run in one-by-one mode
passes: pass struct wldbg_pass * as an argument instead of void **data

This way we don't need to recast the data all the time and the user
can modify the content of the struct depending on arguments passed
to init function.
add .gitignore
passes: add description

Add pointer into wldbg_pass where pass can store its description.
interactive: add basic interaction capabilities
wldbg: add exit flag

This flag is used to indicate that wldbg should exit (for some reason).
If error flag is not used, wldbg should exit with success.