Global configuration settings

[raloos]

We need global configuration settings such as the default OpenCV directory and a way to access these variables by the components and processors.

[Robnocop]

Thought this was allready done with the common.pri?
Or do you also want to automatically read these variables from the environment?

[raloos]

The common.pri file is a place to store compile time information. It is part of a QMake file, which is like a platform agnostic make file.

This issue talks more about the runtime configuration settings. For instance, some processors want to open certain files stored in the OpenCV directory. There should be a way to store that directory for all processors, so you don't have to enter it separately in each processors configuration. We already store some variables in a platform agnostic way using the Qt framework in Pipeline.cpp. This should be extended in some way.