correct mistake in lvm part
Merge pull request #11 from budnyjj/master

correct mistake in lvm part
Reworked first part of networking lecture
Merge branch 'master' of github.com:d4s/linux_courses
Disk presentation
Merge branch 'master' of ssh://github.com/d4s/linux_courses
Reworked iptables, routing and final network practice.
Merge branch 'master' of https://github.com/d4s/linux_courses
Some initial slides for bash