- make ignoreAdd a little more verbose.

- make ignoreAdd a little more verbose.
- added factoidPreventForgetLimitTime. if a factoid exceeds this age,
  prevent forget.
- added factoidPreventForgetRedirect. if this factoid is redirected to
  by other factoids, prevent forget.
- don't evaluate dollar vars in factoid request if it's a factoid
  command.

git-svn-id: https://svn.code.sf.net/p/infobot/code/trunk@534 c11ca15a-4712-0410-83d8-924469b57eb5