spacemanager: Rewrite command line interface

The patch more or less rewrites all space manager related admin commands.

The following commands are removed:

ls
ls file space tokens
listInvalidSpaces
listFilesInSpace
removeFilesFromSpace
remove file
reserve
release
update space reservation

The following commands are added:

ls spaces
ls files
reserve space
update space
release space
release file

The new commands should offer greater flexibility and more concise output.
Documentation has been added for all commands. Options for almost all
commands have changed.

Note that although commands have been rewritten to make use of the
annotation syntax, the point of this patch is the changed user experience,
not the change of implementation.

Internal database keys like the link group id and the file reservation id
are no longer exposed through the user interface. Group (which confusingly
could be both group and user name) and role fields are presented as a
unified owner, which may be a user name or an FQAN. Various list commands
try to hide irrellevant information, dynamically adding columns to the output
suitable for the requested information.

The code was refactored such that the CLI appears in its own class. The link
group import code has been moved to its own classs too. Commands with blocking
code (ie database operations) are now executed on a thread pool to prevent
blocking the message thread.

The RESERVED state of files has been renamed to ALLOCATED to better reflect
how it is used and to be consistent with the terminology of the aggregation
field in space reservations.

The database interface has been extended with a criterion API to allow
flexible querying.

Target: trunk
Require-notes: yes
Require-book: yes
Acked-by: Dmitry Litvtintsev <litvinse@fnal.gov>
Patch: http://rb.dcache.org/r/6415/