fix utils.grep __in and __notin filters

Since grep iterates over search parameters passed as array
and trims the result set after each iteration __in and __notin
don't work correctly as a prior filtering run might exclude results
that a second run might match.
tests for untested utils.grep methods
tests for grep_to_livestatus
Merge pull request #121 from pall-valmundsson/grep-to-livestatus-tests

tests for grep_to_livestatus
Added icinga.cfg to autodiscovery

Thanks to Andreas Falk for supplying a patch.
Merge pull request #120 from pall-valmundsson/grep-tests

Bugfix and tests for utils.grep
updated restructure_config_files example.

Explicitly set new filename for clarity.
Fix host.delete() not deleting services

host.delete() now only skips deleting services if they are applied to a hostgroup