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
Don't use destructive Array#concat for Liquid Attribute arrays
Remove overly specific css from site template
Merge pull request #1574 from Aptary/simplified_css

Remove overly specific css from main.css in site_template
Update history to reflect merge of #1574
Merge pull request #1571 from mojombo/non-destructive-array-concat

Use + instead of Array#concat
Update history to reflect merge of #1571
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