Revert "Add code to VFS hashtable driver to allow stream data to be returned"

This reverts commit 6fb5ebed4b51c91b1d3a411b7295edf009803d44.

Keep base Vfs driver pristine.  Will add this to Core-specific Vfs
driver instead.
Add Core-specific VFS HashTable driver

Uses Horde config for VFS.

Also allows handling that handles filenames and streams. This is an
optimization for common use cases in Horde applications - working with data
stored in temporary files that have been uploaded from the browser.
Update CODING_STANDARDS re: FNV1-32 hashing
SHA1 hash the VFS storage key
Add user information to Horde_Data_Storage key