index: Don't drop query parameters when redirecting to dashboard
iframe: Load JavaScript even when 'isIframe' is true
Use lowercase username and user groups for loading user permissions and restrictions
Resources: Support type 'ini' yet only in the resources.ini

Configuring the resource type 'ini' via the web interface is not yet possible.
lib: Add UserGroupBackend as base class and factory for user group backends
lib: Replace Membership with IniUserGroupBackend
lib: Add DbUserGroupBackend
DbConnection::__construct(): Set prefix if configured
Auth: Load user groups using the new user group backends
schema/mysql: Add group and group_membership tables
schema/mysql: Add user and user_preference tables
Use mt() in the monitoring module instead of just t()

fixes #7330
LDAP Auth: Make group loading really optional

fixes #7432
logging: Fix that setting a numeric log level is flawed
PHP: avoid short tags <?
Command transport: Show helpful exception messages

refs #7437
Fix CSS syntax errors
monitoring: Remove 'Remote' prefix from the remote instance form elements' labels

The 'Remote' prefix of the remote instance form elements' labels is superfluous because the
instance's type already tells that it's remote.
monitoring: Rename label of the path to the local Icinga command file

Rename 'Local filepath' to 'Command file' because the remote instance form is using 'Command file' too.
monitoring: Translate headings in the config overview