Fix Segfault When Syntax Of A Line Under [applicationmap] Is Invalid

When processing the lines under the [applicationmap] context in features.conf, a
segfault occurs from attempting to process a line with an invalid syntax
(basically missing most of the arguments).

Example:
[applicationmap]
automon=*6

* This patch moves the checking for empty arguments to before they are accessed.

* Also, checked the "todo" comment and removed it.  Some applications do not
  require arguments.

(closes issue ASTERISK-22416)
Reported by: CGI.NET
Tested by: CGI.NET
Patches:
    asterisk-22416-check-syntax-first_v2.diff by Michael L. Young (license 5026)

Review: https://reviewboard.asterisk.org/r/2803


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/1.8@399304 f38db490-d61c-443f-a65b-d21fe96a405b