lib/initscript: daemonize

Starts scripts/commands in background using start-stop-daemon.
lib/, scripts/: cmdpool

Asynchronously runs commands and keeps track of them (output,
returncode, ...). See in-code documentation for details.
lib/initscript/daemonize: minor cleanup
lib/cmdpool: doc
move scripts/cmdpool/{,cmdpool-}runcmd.sh
lib/scriptinfo.bash: whitespace change
lib/argparse: count args
lib/cmdpool, cmdpool_stop(): fix exe_name

+ remove debug print
lib/strutil/stdstr: str_startswith(), str_endswith()
scripts/cmdpool: cmdpool-manage

"frontend" for cmdpool
cmdpool-manage: move DEFAULT_X_CMDPOOL_RUNCMD to libdir
cmdpool-manage: 'wait' command
cmdpool-manage: cleanup help message

+ print help message if no args given
lib/function/defined: call_if_defined_else_false()
move cmdpool-manage functionality to lib/
lib/cmdpool/manage/actions/argparse, help message

In cmdpool_manage_print_default_help():
 dynamically call help message generating functions
generate.py: fix typo, add --shlibcc-arg option
generate.py, --shlibcc-arg: "encode" args

shlibcc options (--longopt,-shortopt) have to be prefixed with an "^".
lib/cmdpool: fixup (#1)
cmdpool-runcmd.sh: create "stopped" file

when catching signals: write SIGTERM/SIGKILL to <slot dir>/stopped