A few annoyances and missing references have been fixed - with a huge improvement for PHPStorm users.
Today the ViewHelper references have been updated to fix a few incorrect values and XSD files incompatible with the PHP namespaces we switched to have been updated (and in extension of this, the missing references for the development branches of our extensions). Perhaps most importantly, the arguments in references are now correctly displayed - within the limitations posed by the standard XSD format. Basically this means that ViewHelpers which require object instances as parameters, will display as "mixed" or "anySimpleType" in the type column. In these cases the actual expected type is prepended to the description - but this only works for XSD files we will be generating in the future, the current archive of XSD files will not be updated (but you are welcome to contribute fixed versions! Get in touch with us if you do).
Since Fluid only requires the xmlns on the container tag in your template, you only need to copy/paste the example namespace inclusion from the landing pages of the extension you wish to use. Make sure you select the right version!
You do not need to include the namespacename:schemaLocation unless you are convinced your editor supports this. The sad news is that in all likely it does not.
Congratulations on your choice - you only need to copy both the xmlns:namespacename and namespacename:schemaLocation in order to enable full-on autocompletion for all Fluid ViewHelper tags. Zero configuration needed. PHPStorm will download (and cache) the schema file, only checking it for updates on application startup and only downloading it when updates are needed. Pointing the schemaLocation parameter to another version of the XSD file also means the autocompletion feature switches to this version.
The changes are also available in EXT:schemaker on github and will be released on TER as well shortly.
The FluidTYPO3 Team