model: separate metadata from dataflow

just to make things cleaner
andorcam3: improve log when camera is not found

So far it reported an ATError "index not found" which is not very obvious to the user.
odemisd: avoid duplicate log when instantiating model

The rule is: if you re-raise an expection, don't call logging.expection() (but just logging.error())
config: add dependency on numpy

as noticed by Kimon, dependency on numpy was missing. (it was not a big problem as it was indirectly required anyway)
Report magnification and pixelSize in case of failure
Minor fix in MakeReport
driver simsem: fix metadata being tuple

typo
Merge branch 'master' of vpn.delmic.com:odemis