ref #1 improve message of handling mojibake

- add encoding error message
- fix trivial mistake
Merge branch 'master' into 3_improve_of_handling_mojibake

Conflicts:
	src/main/java/com/change_vision/astah/extension/plugin/cplusreverse/view/CPlusReverseFileChooserDialog.java
	src/main/resources/com/change_vision/astah/extension/plugin/cplusreverse/messages.properties
	src/main/resources/com/change_vision/astah/extension/plugin/cplusreverse/messages_ja.properties
Merge pull request #4 from ChangeVision/3_improve_of_handling_mojibake

ref #1 improve message of handling mojibake