Fix usage of the broargs broctl option

Fixed a problem that would occur when a command-line argument in broargs
contained a space (and the user quoted the argument correctly in broctl.cfg).
The problem was that the shell scripts that run bro were splitting the
argument into separate arguments (due to the embedded space character).

This example broctl.cfg should now work correctly:
broargs = --filter 'not ip6'
Merge remote-tracking branch 'origin/fastpath'

* origin/fastpath:
  Add more links in broctl documentation
Updating submodule(s).

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Change submodules to fixed URL.
Updating submodule(s).

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Fix another usage of the broargs broctl option

This change should have been included in the previous commit.
Merge remote-tracking branch 'origin/master' into topic/dnthayer/broargs
Update 'make dist' target.
Merge remote-tracking branch 'origin/topic/dnthayer/broargs'

BIT-1084 #merged

* origin/topic/dnthayer/broargs:
  Fix another usage of the broargs broctl option
  Fix usage of the broargs broctl option
Merge branch 'master' of git.bro-ids.org:broctl
Updating submodules.
Fix for setting REPO in Makefile.
Updating submodule(s).

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Updating submodule(s).

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Improve portability of shell scripts used by broctl

Fixed usage of some commands (sed, find, grep, ping) used by broctl to
work across a wider variety of systems.
Fix a deadlock when capturing output from local command

When broctl captures output from a command run locally via the
runLocalCmd method, and if the command generates enough output to fill
the OS pipe buffer, then broctl hangs waiting for the child process
to terminate, which never happens because the child process is waiting
for broctl to read from the pipe.  Fixed by using the "communicate"
method (instead of the "wait" method) of the Python subprocess module.
Fix a race condition when sendmail option is empty string

If the broctl sendmail option is set to an empty string (this
indicates that the user does not want email sent), then when
broctl execs the shell script to send mail it just exits immediately
(as expected) which triggers a race condition on some systems that
terminates broctl because the child process exits before broctl
can send input via the stdin pipe.  Fixed by not executing the shell
script when the sendmail option is an empty string.
Updating copyright notice.
Updating submodule(s).

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Updating submodule(s).

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