Mark some more variables as static or include the appropriate header

Detected by clang's -Wmissing-variable-declarations.

From: Andres Freund <andres@anarazel.de>
Minor pg_dump improvements

Improve pg_dump by checking results on various fgetc() calls which
previously were unchecked, ditto for ftello.  Also clean up a couple
of very minor memory leaks by waiting to allocate structures until
after the initial check(s).

Issues spotted by Coverity.
Avoid printing uninitialized filename variable in verbose mode

When using verbose mode for pg_basebackup, in tar format sent to
stdout, we'd print an unitialized buffer as the filename.

Reported by Pontus Lundkvist
Limit pg_basebackup progress output to 1/second

This prevents pg_basebackup from generating excessive output when
dumping large clusters. The status is now updated once / second,
still making it possible to see that there is progress happening,
but limiting the total bandwidth.

Mika Eloranta, reviewed by Sawada Masahiko and Oskari Saarenmaa
Focus on ftello result < 0 instead of errno

Rather than reset errno (or just hope that its cleared already),
check just the result of the ftello for < 0 to determine if there
was an issue.

Oversight by me, pointed out by Tom.
Further pg_dump / ftello improvements

Make ftello error-checking consistent to all calls and remove a
bit of ftello-related code which has been #if 0'd out since 2001.

Note that we are not concerned with the ftello() call under
snprintf() failing as it is just building a string to call
exit_horribly() with; printing -1 in such a case is fine.
Use memmove() instead of memcpy() for copying overlapping regions.

In commit d2495f272cd164ff075bee5c4ce95aed11338a36, I fixed this bug in
to_tsquery(), but missed the fact that plainto_tsquery() has the same bug.
Fix WakeupWaiters() to not wake up an exclusive locker unnecessarily.

WakeupWaiters() is supposed to wake up all LW_WAIT_UNTIL_FREE waiters of
the slot, but the loop incorrectly also woke up the first LW_EXCLUSIVE
waiter, if there was no LW_WAIT_UNTIL_FREE waiters in the queue.

Noted by Andres Freund. This code is new in 9.4, so no backpatching.