* fix unhandled errors
* fix unhandled error in cache package test
* omit variable type
* omit variable type
* rename variable because collide with the imported package name
* handle file error on closing
* fix unhandled in common_linux.go
* fix unhandled errors in helpers_test.go
* fix unhandled errors in listen_test.go
* remove unused parameter in emptyHandler method
* Fix padding around app name in startup message when it contains non-ascii characters
* fix conflict, allow ending space only for odd length strings
* move startup message tests to listen_test.go