bump up version to 0.2.8

fix jump back action not to crash when the buffer is edited

refactor drawing command line and completion candidates

use explicit argument indexes in fmt.Sprintf and fmt.Errorf

fix nil pointer dereference in tests

bump up version to 0.2.7

fix nil pointer dereference in tests

bump up version to 0.2.7

recognize bang of :wq command to quit on unsaved changes

propagate bang of :wq command to quit on unsaved changes

use CHANGELOG.md instead of Gopkg.toml in completor tests

add editor test for moving cursor from command line

add editor test for moving cursor from command line

add editor test for moving cursor from command line

add editor test for moving cursor from command line

add editor test for moving cursor from command line

implement command line completion of command names

implement command line completion of command names

wrap long lines in buffer tests

fix goroutine leaks and close channels in window tests

fix goroutine leaks and close channels in window tests

fix goroutine leaks and close channels in window tests

fix goroutine leaks and close channels in window tests

fix goroutine leaks and close channels in window tests

fix goroutine leaks and close channels in window tests

fix goroutine leaks and close channels in window tests

fix goroutine leaks and close channels in window tests

fix goroutine leaks and close channels in window tests

remove unused receiver names

remove unused receiver names