Improved the autocomplete input for modules

* pandora_console/include/ajax/module.php: Improved the module name search.

* pandora_consle/include/functons_html.php: Improved the autocomplete input
	for modules.
Improvements on the Planned Downtime section

* pandora_console/godmode/agentes/planned_downtime.editor.php: Fixed an error
	which made impossible the creation of new periodic downtimes.

* pandora_console/godmode/agentes/planned_downtime.export_csv.php: Added file.
	Exports the planned downtimes list to a CSV file.

* pandora_console/godmode/agentes/planned_downtime.list.php: Added a new form
	to filter the list. Added pagination. Changed the items order. Error fixes.
Now the planned downtimes CSV shows the affected elements
Added support to create scheduled downtimes with past dates

* pandora_console/godmode/setup/setup_general.php,
  pandora_console/include/functions_config.php: Added a config token
	to allow the creation of scheduled downtimes in the past.

* pandora_console/godmode/agentes/planned_downtime.editor.php: Now
	is possible to create a scheduled downtime with a past date
	if the config token is activated.
Improved the warning messages on the planned downtimes edit section
Fixed the date filter of the list
Improved the planned downtimes calculation for the SLA functions

Now the functions "reporting_get_agentmodule_sla" and
"reporting_get_agentmodule_sla_array" do the planned downtimes
calculation correctly.
Moved some code to the new function "reporting_get_planned_downtimes_intervals"
Added the function "reporting_get_planned_downtimes".

* pandora_console/include/functions_reporting.php: The new function
	"reporting_get_planned_downtimes" return a planned downtimes
	array with the planned downtimes that affect the passed modules
	on an specific datetime range.
	Improved two function calls on the function
	"reporting_render_report_html_item".
Improved some functions

* pandora_console/include/functions_reporting.php: Fixed the function
	"reporting_get_planned_downtimes". Added a table to the SLA
	reports which shows the planned downtimes that affect the
	SLA report elements.
Added new help files to explain the datetime configuration of a planned downtime
Error fixes and improvements. Improved the help tips of the planned downtimes editor
Merge branch 'feature/ticket#1243-PlannedDowntime' into develop