added a changelog entry and set the version for 6.8
Merge remote-tracking branch 'antage/golang-6' into ragel-6
Merge remote-tracking branch 'antage/golang-6' into ragel-6
substitue 'build' arg through GOBIN
added Anton Ageev and Kamil Klimkiewicz to credits
updated release date
updated credits
'//line' directive support in Go code generator