srm: Refactor Scheduler

This is the first iteration to clean up the Scheduler class. The
patch mostly addresses logging and locking issues, and also replaces
a number of chained if-statements with switch.

Appologies for auto-reformatting, but the existing indentation was
too inconsistent to work with.

I deliberately did not make major changes to the logic or error
messages. That will be done in subsequent patches.

Target: trunk
Require-notes: no
Require-book: no
Acked-by: Paul Millar <paul.millar@desy.de>
Acked-by: Dmitry Litvintsev <litvinse@fnal.gov>
Patch: http://rb.dcache.org/r/6199/
srm: Get rid of dead exception code in Scheduler

Target: trunk
Require-notes: no
Require-book: no
Acked-by: Paul Millar <paul.millar@desy.de>
Acked-by: Dmitry Litvintsev <litvinse@fnal.gov>
Patch: http://rb.dcache.org/r/6206/
srm: More Scheduler refactoring

Target: trunk
Require-notes: no
Require-book: no
Acked-by: Dmitry Litvintsev <litvinse@fnal.gov>
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: http://rb.dcache.org/r/6209/
srm: Some more refactoring of Scheduler

Target: trunk
Require-notes: no
Require-book: no
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: http://rb.dcache.org/r/6212/
srm: Fix compilation error introduced by bad merge

Target: trunk
Require-notes: no
Require-book: no
Patch: none
billing: Add shebang header to indexer cronjob

Addresses an issue with the billing indexer cronjob, that
prevented it from being executed.

Target: trunk
Request: 2.7
Require-notes: yes
Require-book: no
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: http://rb.dcache.org/r/6249/