sqlite error if running khal without first running khal --sync

[catern]

If khal or ikhal is run without first running khal --sync, a user will get an error looking something like the following.

Traceback (most recent call last):
  File "/home/catern/src/khal/virt/bin/khal", line 5, in <module>
    pkg_resources.run_script('khal==0.1.0.dev', 'khal')
  File "/home/catern/src/khal/virt/lib/python2.7/site-packages/pkg_resources.py", line 540, in run_script
    self.require(requires)[0].run_script(script_name, ns)
  File "/home/catern/src/khal/virt/lib/python2.7/site-packages/pkg_resources.py", line 1462, in run_script
    exec_(script_code, namespace, namespace)
  File "/home/catern/src/khal/virt/lib/python2.7/site-packages/pkg_resources.py", line 41, in exec_
    exec("""exec code in globs, locs""")
  File "<string>", line 1, in <module>
  File "/home/catern/src/khal/virt/lib/python2.7/site-packages/khal-0.1.0.dev-py2.7.egg/EGG-INFO/scripts/khal", line 72, in <module>

  File "build/bdist.linux-x86_64/egg/khal/controllers.py", line 178, in __init__
  File "build/bdist.linux-x86_64/egg/khal/backend.py", line 440, in get_allday_range
  File "build/bdist.linux-x86_64/egg/khal/backend.py", line 164, in sql_ex
sqlite3.OperationalError: no such table: simple_d

[geier]

I agree, a more informative error message would be really nice.