cleanup.
A couple of style nits
Remove a pseudo-bogus test for pthreads in the manager process.

The subsequent cleanup/separation of .h files makes this test
much less important, and it's not like it is a conclusive or
comprehensive test in the first place.

Fixes	#1230
Add a BAN_Shutdown() routine that is called before STV_Close(), and
makes sure that the ban lists will not change until we exit.

This is to give persistent stevedores a chance to clean up their ban
lists without having to worry about the lists changing under them.
Allow reload of a series of persisted ban specs in one go.
Drop the internal ban delimiters in the persistent ban lists, and
reload all the statements in one go.
Don't report ban_magic to the stevedores on insertion, but delay it
until ban compile.

Document the reason.
Fix bug in smp_baninfo causing duplicate ban entries.
Report BAN event persistence failures back to cache_ban.c
Add a facility to export a complete ban list to the stevedores. Call
this on startup, after reading the persisted ban lists, to make sure
all stevedores has all the bans from every stevedore stored.
Try to export the ban list on STV_BanInfo failures.

When STV_BanInfo fails, it means the stevedore has run out of space to
persist the list. An export should descrease the size.
Export the ban list on shutdown to compact it
Add a test case for ban list syncing across silos
Fix test case

Varnishtest -storage option can not be specified multiple times to
append. Fix the test case to list all the silos in one -storage
option.
Set the split character back to '=' after applying the runtime
parameter to preserve the arguments as seen e.g. ps.

Fixes: #1238
Constify VSB_len() and VSB_data()
Assert BAN_Insert() success.
Avoid "const const" duplication
Constification
Spelling fixes.

Submitted by:	 Federico G. Schwindt

Thanks!