sxadm: run fetchnodes for --info and --force-* (bb #802)

save the nodelist changes on --force-*, but not on --info
(--info should be a readonly operation).
avoid double slash in local paths (bb #392)
volume deletion (server)
delete local configuration when removing volume
add breadcrumbs for sxvol remove
fix ftw inclusion
use path limit in bytes (bb #311)

The real limit depends on nginx's buffer size (large_client_header_buffers),
where the full request line including the verb, volume name, url-encoded path and \0 has to fit in 8k by default.

10 + SXLIMIT_MAX_VOLNAME_LEN + SXLIMIT_MAX_FILENAME_LEN*3 <= large_client_header_buffers
forbid non-recursive operations on volume root
fix message
do not empty check volumes we don't own
add breadcrumb for sxrm volume
add man page for sxvol remove
implement sxacl --token (bb #810)
use sxacl useradd --force-key

instead of sxacl useradd --token
add --force-key man entry
add SEE ALSO, minor fixes
bump version number
set default volume size to 500G (bb#813)
temporary work-around for bb#813
strdup the url from CURLINFO_EFFECTIVE_URL

queue_next_inactive can indirectly free the url (when setting a new one).