Linked to LCGDM-2843

Improved synchronization script code to be able to use it while
DPM/dmlite daemons are still running. Most important is dir-size
operation which can take quite a lot of time and could be used
only during scheduled downtime - now dir-size update can be done
without stopping DPM, but to be able to perform such operation
it is necessary to create snapshot of few file metadata/replica
columns. This snapshot can be done only with additional FILE
privilege and sufficient space (additional 20% of current cns_db
size) for temporary dump file and database table. It is also
necessary to manually remove temptable_fix_dir_size_"ts" file
from database server stored usually in /var/lib/mysql/cns_db
directory.
Also spacetoken-size fixes should now be more safe to run while
DPM/dmlite is online, but it is not really possible to make
consistent updates while DPM is running. On the other hand this
update is so small/fast that is should mostly work and one can
call script with this parameter several times to converge to
reasonable close numbers for spacetoken disk occupancy.
Class CachedFullPath that provides efficient fileid to full path
mapping was also mostly rewritten to be able to deal with data
snapshot necessary for online dir-size updates.

This reverts commit 9205168f.

Refactor the transactions used for the space accounting. May make it more precise in the case of high concurrency.

Fail while parsing command line options in case user specify
base path where tests for directory space usage fails by desing
because they are outside of head.dirspacereportdepth configuration

Publishing storagesummary.json as a file stored in DPM can fail
in many different ways and this commint adds necessary scripts
and configuration that allow us to provide WLCG SRR directly via
CGI interface without storing intermediate files. SRR is available
by HTTP protocol at URL /static/srr

Properly treat EEXIST in dome_makedir. Always forward the original error message if a makedir goes wrong