Test Writer in post-reboot conditions

[fisherab]

Writer and the methods that use it, i.e. /put and /delete have been changed last minute.
There are some simple tests written for them, but they haven't been tested in conditions
after rebooting the system when there are some requests to be resumed. Especially /delete
can be tricky here, as some of the files or information in the database may no longer
exist. 

In case of deleting a whole dataset its location is stored in IDS database, so the
files associated with it can still be found and deleted. In case of single datafiles,
the information of their dataset can be retrieved from ICAT and packaging and writing
this dataset is all that is needed.

Original issue reported on code.google.com by wojtasskorcz on 2013-09-27 14:50:28

[fisherab]

(No text was entered with this change)

Original issue reported on code.google.com by dr.s.m.fisher on 2013-11-27 11:53:40