* adds osclass chart
* lock mariadb chart requirement to 0.5.x series
* explicitly set default `imagePullPolicy` to `IfNotPresent`
* osclass: add alpha and beta storageclass annotation support
* osclass: increase resource name truncation and trim - suffix
* update osclass image to `bitnami/osclass:3.7.0-r2`
* osclass: bump image to `bitnami/osclass:3.7.0-r3`
* osclass: updated to image `bitnami/osclass:3.7.0-r4`
Contains fix for https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2017-5340
