fix #2101
Merge pull request #2102 from guangyang/release-0.7.1

fix #2101
update readme and changelog for 0.7.1
Merge pull request #2110 from guangyang/release-0.7.1

update readme and changelog for 0.7.1
add new storage cmdlets to changelog and readme
Merge pull request #2111 from guangyang/release-0.7.1

add new storage cmdlets to changelog and readme
Merge pull request #2112 from WindowsAzure/release-0.7.1

Release 0.7.1
Merge pull request #2113 from WindowsAzure/master

Merge master into dev