fall back to getLocalFile if storage doesn't support fseek
implement ftell stream wrapper and fix return value from fseek stream wrapper
extend the encryption stream wrapper to handle local files and add a fall back for file size calculation if the storage doesn't support fseek
test for isEncryptedPath()
add test for the stream wrapper to read encrypted files from the system folder /tmp
Merge pull request #6495 from owncloud/enc_fseek_fallback

Added fseek fallback to the encryption app