Merge pull request #1782 from WindowsAzure/release-0.6.17

Release 0.6.17
Update version to 0.6.18
Merge pull request #1805 from markcowl/release-0.6.18

Update version to 0.6.18
Merge branch 'release-0.6.18' of https://github.com/WindowsAzure/azure-sdk-tools into release-0.6.18
update changelog and readme
Merge pull request #1814 from guangyang/release-0.6.18

update changelog and readme
Merge pull request #1818 from WindowsAzure/release-0.6.18

Release 0.6.18 to Master
work with sastoken in connection string and fix typo
metrics should be valid table name
Set/Get storage service properties
set retentiondays=0 to disable logging/metrics
generate sas token for table, queue, blob
generate sas token for table, queue, blob
apply review comments
apply review comments
apply review comments
apply review comments
fix typo
merge sas branch and resolve the merge conflicts
fix bugs in disable logging/metrics