Revert "remove useless files"

This reverts commit b884bbbfac09e3aa2823b086dde0af9a98e892fd.
change note.txt
add note.txt
Revert "Revert "remove useless files""

This reverts commit 0f83f1106ef426bd4b7d69a1485dafafb07ccbb9.
Update and rename note.txt to postfix.txt

Add some knowledge about postfix
add txt
add send_mail.txt
add new txt
Merge branch 'master' of https://github.com/zlroy1023/isepldc2014
Merge pull request #72 from a1mery/master

parsing with sed
Merge pull request #73 from peiyunli/master

add new txt
Merge pull request #74 from zlroy1023/master

commit
Merge pull request #75 from abgailjt/master

add new txt
Rename postfix.txt to notes.txt
Merge pull request #76 from zlroy1023/patch-1

Rename postfix.txt to notes.txt
cours
cours
Virtual machine
Merge pull request #77 from john2512/master

cours
Merge branch 'master' of github.com:nicolasroger17/isepldc2014