add encoding for configuration
write document for config.encoding
consider a case of "site" is unavailable in Convertible
read_yaml to accept optional parameter to override defaults
Make TestConvertible to pass with utf-8 encoding
Pass encoding parameter as string, not an object
Invoke File.read with or without options depends on Ruby version

- Extract option fetch method as a separate method
- Added File.read_with_options method to use
- With performance fix
Documentation update for the encoding configuration
Change error handling for gist tag: raise exception
fix tests for new behaviour
Change error handling in 'post_url' tag: raise exception
raise exceptions in include tag
'gist' tag: switch to ArgumentError exception class

SyntaxError is reserved for Ruby's internal use.

Adjust the tests, including the call to liquid to
make it rethrow ArgumentErrors.
Merge pull request #1449 from shigeya/config-encoding-and-yaml-opts

Adding "encoding" configuration (4th version)
Update history to reflect merge of #1449
Merge pull request #1 from mojombo/master

sync
Update pagination example
Remove gist URL in pagination docs.
Update history to reflect the merge of #1577.
Print server address when launching a server.

Related to: https://github.com/mojombo/jekyll/issues/1583