Users can have preferences
More graceful reaction when there are no preferences (avoiding NPE)
Custom exceptions should never inherit from Throwable directly
Set invalid (but non-empty) password for accounts synced from LDAP

Accounts which have been synced from an LDAP directory had an password by default.
Unfortunately our validation didn't take this into account and the automatic creation
of the user account in Graylog2 subsequently failed.

User accounts synced from an LDAP directory will now get an invalid but non-empty
password. This prevents the failing of our validation but still prevents users from
logging into Graylog2 when the LDAP server isn't available.

Fixes #661
Don't check open file limit on Elasticsearch nodes running on Windows, fixes #715
Use the right collection for dashboard positions
Add null-check for Elasticsearch node "os.name" (just in case)
Change return type of PluginMetaData from URL to URI
Merge branch 'issue738'
Updated version number to 0.23.0-SNAPSHOT
Remove deprecated Alarm, AlarmReceiver, and Transport classes
Catching the right exception so generating node file does not fail.
Merge branch 'master' of github.com:Graylog2/graylog2-server
Recording metrics for stream rule timeouts and stream faults.
Fix user creation from incomplete LDAP data

In commit 23aa3e4 only the creation of users with missing passwords has been fixed.
Unfortunately there are cases in which users from LDAP are also missing some other
attributes like the full name/display name or an email address.

Since most of these attributes are optional, users will now have an email address
constructed from the user name and `localhost` if the email address is missing.
The full name attribute has been made optional.

Refs #661, refs Graylog2/graylog2-web-interface#905
Shuffling around initialization/checking configuration of inputs.

Adding actual launching of persisted inputs on radio nodes.

Fixes #719
Revert "Not scanning for alerts when message processing is disabled."

This reverts commit e3112d6a49f73d9d9b79e31f085e003de06af006.

This has been reverted because it is semantically wrong to disable
checking for alerts when message processing is disabled, because even
if it is disabled on master (where the alert scanning is run) it might
be enabled on other nodes, so scanning is still necessary.

Conflicts:
	graylog2-server/src/main/java/org/graylog2/periodical/AlertScannerThread.java
Removing doubled input initialization.

Fixes #720
Fixing NPE on Input launch on server.
Adding creation date of input to serialisation.