add sha1sum, sha224sum, sha256sum, sha384sum, and sha512sum pages
add pwd page
Merge pull request #216 from felixonmars/pwd-page

add pwd page
Merge pull request #215 from felixonmars/shaNsums-pages

add sha1sum, sha224sum, sha256sum, sha384sum, and sha512sum pages
ping page: add -n param
Merge pull request #217 from felixonmars/ping-page

ping page: add -n param
Added invert match parameter.
Fixed token syntax.
Added saltstack.
Merge pull request #218 from akoenig/grep-invert

[grep] Added invert match parameter.
Merge pull request #219 from notpeter/master

Add saltstack.
added iostat.md
mdadm - RAID management utility
Merge pull request #221 from Like-all/master

mdadm - RAID management utility
Merge pull request #220 from tim-sebring/master

added iostat.md
sepearted -> separated
Added pushd.md
Moved pushd.md to common folder
GPG: Parameter for importing a public key.
Merge pull request #224 from akoenig/gpg-import

GPG: Parameter for importing a public key.