File selector on text box block config form closed by default (Bug #1311860)

Currently it is always open - this patch sets it up to be closed and
allows it to be toggled open/closed

Also aligned the close 'X' to the right

Change-Id: Id92428e5345748826a4640f91f56b268e7b01c47
Signed-off-by: Robert Lyon <robertl@catalyst.net.nz>
Merge "File selector on text box block config form closed by default (Bug #1311860)"