* adds rekeying and resizing controls to config+report api of file vault
* moves common types of file vault to file_vault/include/file_vault/types.h
to be included by other components
* fixes wrong type of nr_of_clients fields in file_vault
* introduces the file_vault_gui component that is a minimal graphical front end
for the file vault based on the dialog lib and that uses the
config+report api of the file vault as back end
Ref #5190
