WebHelp: HOWTO MARC document update

* Updates HOWTO MARC file with all the most up to date information
  on the MARC conventions at CERN and in INSPIRE.
BibHarvest: optional JSON dependency

* JSON is only optional dependency, so we should not require it,
  but rather silently fail if it is not available on older Pythons.
  (The site will work generally well, modulo certain functionality.)
Merge branch 'maint-1.0'

* maint-1.0:
  BibHarvest: optional JSON dependency
  WebHelp: HOWTO MARC document update
  textmarc2xmlmarc: fix handling of BOM
  BibIndex: Greek stemmer improvements

Conflicts:
	modules/bibharvest/web/admin/oaiharvestadmin.py
	modules/webhelp/web/admin/howto/howto-marc.webdoc
I18N: update PO files for the release of v1.0.0
Merge branch 'maint-1.0'

* maint-1.0:
  I18N: update PO files for the release of v1.0.0
Invenio v1.0.0
Merge branch 'maint-1.0'

* maint-1.0:
  Invenio v1.0.0

Conflicts:
	Makefile.am
	THANKS
BibSched: fix running of concurrent tasks

* Fixes handling of sequenceid for concurrent tasks that have
  no sequenceid.  (closes #923)
BibSched: fix get_tasks_to_sleep_and_stop task set

* Adds missing sequenceid element when handling get_tasks_to_sleep_and_stop.
  (closes #924)
BibSched: improve sequenceid handling

* Fixes some bugs where the sequenceid was not considered in the Python code.

* Adds MySQL index for sequenceid.

* When handling several tasks with the same sequenceid, raise their priority
  to the maximum priority among them (so that the taskid order is still
  respected).

* Don't consider None as a sequenceid.
BibSched: avoid double run tasks in manual mode

* In bibsched monitor, when in manual mode, if someone
  presses "R" twice (or more), too quickly, avoid executing
  the task more than once. (closes #914)
installation: more info about max_allowed_packet
I18N: updates to Greek translation
Merge branch 'maint-1.0'

* maint-1.0:
  I18N: updates to Greek translation
  installation: more info about max_allowed_packet

* Merge notes: el.po was prepared for master, but was first committed
  to maint-1.0 and only then here, so that Greek translation would be
  updated also for Invenio v1.0 release series.

Conflicts:
	po/el.po
BibIndex: new unit tests for the Greek stemmer
WebSearch: fix collection order on the search page

* Collection list on the search page should follow the same order
  of sub-collections as they appeared on the starting collection
  splash page from where the given search originated. (closes #900)

* Cherry-picked from 8ef26dd58830455e09a6e10331e12d91b9c7f494.
BibEdit: bugfix split of subfields
BibFormat: add new bfe_copyright

* Adds new bfe_copyright BibFormat Element that displays copyright
  and license information based on MARC tags 540 and 542.
demo site: new Video collection

* Adds new Video collection showcasing video treatment.  (Contains one
  demo video borrowed from CDS.)

* Improves guess_primary_collection guessing algorithm for collections
  defined as 980:"VIDEO" or 980:VIDEO.

* Corrects reportnumber format for DEMOVID.
dbquery: fix collection dbquery regression tests

* Fixes regression tests after the recent introduction of Video
  collection.