set password for shared links when the user press enter and when he leaves the password field
some more usability improvements:

merged pull request https://github.com/owncloud/core/pull/121 into this patch with fixes for all issues mentioned in 121
[files_external] mount filesystems for all users
[files_external] fix config gui for all users
[files_external] fixes #290

Background:
the previous opendir call on a file is implemented as a smbclient call:
smbclient -N -U 'user%******' -d 0 //server/testsmb -c 'dir "folder/file.txt/*"

A Samba server will return NT_STATUS_OBJECT_PATH_NOT_FOUND which returns false on the stream wrapper implementation.
A Windows Server/Workstation will return  NT_STATUS_INVALID_PARAMETER which will result in an call to trigger_error() and death :-(

Fix:
According to the stream wrapper documentation a call to filetype() will call stat() on the stream wrapper and interpret the the result correctly.
This has been tested with Windows 7 and Samba 3.4.3
[files_external] removing function as it's the same in the base class - THX Robin
[files_external] fixing some undefined index
[3rdparty] patching smb4php to allow special characters on file names within SMB shares
LDAP: don't append absolute paths to datadir when determining customized user home, fixes #763
fix increaseSize to also increase the size of the root folder
backport of PR #810
add test case for increasesize
fix increaseSize when called directly on the root folder
fix checking quota in webdav, adding a sabredav plugin
code style changes
throwing InsufficientStorage in case the quota is reached
use username, not passed loginname, might differ
implement getCurrentUser in Sabre Auth Connector, fixes #508
Add an $excludingBackend optional parameter

to the userExists method both in OCP\User and in OC_User.
backport of de34f771c22b9a54fa22d9c00741e362f47c852d