rpm: corrections in the SKIP mechanism

when DB migration failed the log claimed to problem was after SKIP10, but that shouldn't have existed for a long time
when looking at it I found two more misses
rpm: refactoring harvester DB initialization

use a common script for dev and prod
done in preparation for DB migration corrections
rpm: a setup script refactored

suspected that exit in the wrong place caused DB migration not to be run
suspicion was wrong, the problem was caused by dirty build environment, code should be correct
keep the refactored code, structured programming is better after all
rpm: don't run harvester DB initialization if DB exists
rpm: fix syntax error introduced in previous commit
rpm: previous commits tested in autobuild & logs updated
documentation: Installation and upgrade information updated
rpm: change solr storage to /opt/data
rpm: avoid overwriting backups during upgrades

not many upgrades should be made ever, so the number of files is not an issue
better safe then sorry in case we need to debug something
Merge remote branch 'github/master'

Conflicts:
	rpms/kata-ckan-prod/kata-ckan-prod.spec

resolved by combining additions from both branches
rpms: gather all db initialization for extension into a single script

this should also avoid kata-ext db initialization being run when db is kept during rpm ugrade
not yet tested
rpm: bug fix to previous commit, symbolic links updated after renaming file
Merge branch 'aleksi' into uwe (2nd merge attempt, previous merge github/master into master was incorrect)

Conflicts:
	rpms/kata-ckan-prod/kata-ckan-prod.spec

Don't let deleted lines rise from death in conflict resolution as in previous attempt b2e2128
Merge branch containing corrected version of previous merge

Conflicts:
	rpms/kata-ckan-prod/kata-ckan-prod.spec

Conflicts resolved manually
previous commits tested in autobuild and log updated

dev installation log and pip freeze files have been lost