[remind] Filter empty strings from the message

This fixes a problem with the .in command where not all of the arguments for the
duration get applied.
Use input in place of raw_input for python3+

Since the raw_input() function  has been renamed to input in python 3,
we replace it by input() in case willie is run from python3+
Merge pull request #555 from vaz-ar/master

Fix configuration with python 3
[calc] Add guards to pow and mul functions to avoid hangs.

- Fixes #538.

- Removed the drivel from calc when exceptions are raised. Printing the actual
  error might not be pretty, but at least it's not completely useless.
Add code for #564 as a new branch
Fix for #560
[calc] Add timeouts and better formatting to calc.

- Added default timeout of 5s to expression evaluator, that will throw
  an error before evaluating the next statement if the timeout has passed.
  This should stop an expression consisting of several long running
  statements from taking too long.

- Calc now uses general number formatting from str.format to print the
  number according to it's magnitude.

- Fixes bug in Python 2 from #538, where long ints are let through by using
  abstract base class numbers.Integral.
Merge pull request #565 from phantium/ticket564

[adminchannel]Check for channel (half-)operator before action
[translate] Fix bug with the $nickname: "foo"? form
[core] JobScheduler now works on Python 3.4

Fixes #571
[ipython] Don't use deprecated IPython.frontend on newer versions of IPython
[tell] Fix Python 3 support

Fixes #562
Merge pull request #567 from phantium/t560

Add fix for ticket #560
[web] Return status when returning headers

Return status as headers['_http_status'] if return_headers is set to True.
I'm using '_http_status' so it won't override any actual HTTP header that might
be present in the response.

This commit might break your modules if you didn't treat the returned headers
as a plain dict. I doubt anyone actually does that anyway.
[currency] Better error message for invalid currencies

Fixes #552
Fix trigger.admin matching.

- Add $ to the regexp so re.match won't accept a partial match.

- Simplify the re.escaping to make sure it's actually correct.
Fixed issue #577 (.help not working for command aliases)
Merge pull request #578 from flashcactus/master

[core] Fixed issue #577 (.help not working for command aliases)
[Version]Send a little message to the owner and admins when Willie isn't updated.
[Version]Don't PM admins when outdated, only the owner.