Name-space exceptions correctly

+ re-add tc copyright/license to streamWrapperHttpAuth (since they also created that class)
Better authentication failure mode fro SP online
Don't specify SSL version for CURL's - SP no longer seems to like this.
Add deleteAttachment method contributed by @jjworld
Remove getItemVersions as this method currently isn't working/useable. see https://github.com/thybag/PHP-SharePoint-Lists-API/pull/55 & https://github.com/thybag/PHP-SharePoint-Lists-API/issues/54 for more info
Bump version for good measure
Merge pull request #68 from thybag/feature/updates

General updates