Add :force_encoding support to WebsiteAgent.
Add regexp matching support to EventFormattingAgent.

A new setting key `matchers` is added to define regular expression
matching against contents of events and expand the match data for use
in `instructions` setting.
Ignore force_encoding if empty.
Merge pull request #212 from knu/website_agent-force_encoding

Add :force_encoding support to WebsiteAgent.
Add specs for :matchers validation.
Adjust the style to the project's taste after a review.
Add a missing assertion.
Merge pull request #214 from knu/event_formatting_agent-regexp

Add regexp matching support to EventFormattingAgent.
Extract private development information to the wiki
make validate methods as an private method for avoiding to use it as an instance methods
Git +EOL
fix travis error Gem bundler is not installed
travis fix
Merge pull request #219 from rajcybage/validation_in_private

Small refactoring Add validate methods in private for avoiding to use it as an instance methods
Add a setting for using locally installed Graphviz for generating diagrams.

The Google Charts service is only capable of rendering a limited range
of characters, so if you name your agents in an exotic language
generated diagrams are virtually useless being unable to make out.

With this change, Huginn embeds a locally generated SVG diagram instead
of relying on a third-party API if ENV['USE_GRAPHVIZ_DOT'] is set to a
command name/path of dot(1).

While at it:
- Use URI to compose a URL instead of hand-crafting it.
- Make the dot renderer a helper method.