Merge pull request #1 from ryo1kato/master

Show error message when exec() fails
Remove a non-existing function
Change the way to distinguish whether stdout is redirected or not
Change the way to distinguish whether stdout is redirected or not
Typo
Modify the test to fix the exit status and the error comment
Add the exit system call in the procedure of showing error messages
Cleaning
Make Feeder::blank accepts the NULL pointer
Rename the functions for handling cursor in the feeder
Cleaning
fix Feeder::blank() for a blank line
Merge pull request #4 from ryo1kato/issue-3

possible fix for the issue #3 on ryuichiueda/GlueLang
Modify the merge a little
Unify test_all.sh and test_all_mac.sh
Remove warning
Add install and uninstall
Bugfix