Fix multiple problems with the Downtime related views

* Host status not being displayed on service downtimes
* Credentials for host/servicegroups and contactgroups
  were not applied correctly
* Added a filter to support filtering by host_state
  (needed due to the first fix here)
* some smaller cleanup

refs #4205
Fix rendering glitch for booleanImage columns in grids

caused by applying icon-X to the cell css classes, which set the display
mode of those cells to "inline-block", although it should be "table-cell"

fixes #4236
schema: update to 1.9.0, add upgrade scripts for fresh install upgrades

fixes #4309
Fix imports in crypt lib causing ssh commands to fail

This should fix the freezing interface when sending commands
over SSH. The reason was the missing RSA import and invalid
requires the Crypt/RSA.php (those were added by us and are
no fail of the original author)

fixes #4411
Fix selection being corrupted after grid reload

This commit fixes a bug where a grid reload can lead to invalid selections,
as the same rows are selected, even if there's a different ordering of objects
in the new dataset. Now the object_id columns are remembered and used
to determine if a page contains previously selected objects after a reload,
this is implemented in ObjectSelectionModel

refs #4452
Reenable BLOB filtering in UserPreferences by changing cachedPreferences content to SQL data

This avoids problems with too big AppState while editing user
preferences.

fixes #4003
fixes #4062
fixes #4063
Fixed singleton refreshTask for MetaGridPanel

The function requestTask was created as a singleton on object
definiton, which caused all MetaGridPanels to share the same
function.

It is now created on the first refresh for the local scope.

(fixes #4563)
Merge branch 'support/1.9' into next