[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.
pyenchant is now in pip, the refered bug report has been closed
[calc] Add tests for potential problems with the calc module.

- Added as a separate commit to confirm that the problem with .c 0.9*10
  exists and is fixed.
[calc] Fix .calc for expressions where left operand is float.

- Typo in the if-expression caused the fact that input operands are not int
  to be ignored.
[calc] Fix left operand being float for pow expressions.
[web] Fix entity() under Python 3
[web, url] Better IDN support

* Move IDN helper methods to willie.web for easier access from modules
* Make willie.web methods IDN aware
* Python 3 fixes for the IDN support
[core] Workaround bot.connecting missing in python 2.7.3 or older

See issue #559
If this commit helps you then you REALLY need to update your python
install to something newer, for bugfixes and security fixes.
[web] Quote query before doing IDN stuff

This will prevent IDN functions from messing up queries with non-ascii characters
[formatting] Add tools to simplify IRC formatting
[reddit] Stop showing absolute vote counts

Also move to our new formatting API.
[weather] Fix error when no argument is given to setlocation

Fixes #594
Merge pull request #592 from warddr/devreq

pyenchant is now in pip, the refered bug report has been closed
[bugzilla] Use dont_decode in web.get

lxml refuses to parse unicode strings if the string contains an encoding
decleration. This means the bugzilla module has been broken since the
introduction of the decoding capability of web.get and nobody noticed.

This commit fixes that issue.
[bugzilla] Don't output an error if the bugzilla module was not configured

When the bugzilla module is not configured willie would output an error when
encountering a bugzilla link. This commit fixes this issue.
[find] Use the new willie.formatting functions for text formatting
Merge pull request #535 from Beini/remind-fix

[remind] Filter empty strings from the message