pyInterface: improve fileManager

change a lot of different aspects of the fileManager:
1) initialize by a config file. Add keyfile and amplitude file path to config
file. Add filesPerDir to config file which indicates how many amplitude files
can go in one directory.
2) open keyfiles and save the waveName together with the file name in an
instance of the KeyFile class. All keyfiles are saved in a keyFiles list.
3) handle bins only by binID and key files only by keyFileID internally.
4) implement amplitude paths. Change subdir when file limit per directory is
reached.
5) lots of minor bugfixes.
pyInterface: change config __init__ to initialize method

change __init__ method of config class to an initialize method, so we can
return True/False to indicate whether initialization succeeded or failed. Hence
we can have proper exception handling and don't have to use sys.exit(1) if
exceptions do happen. Change files affected by this update accordingly. Also
implement some checks to see if the key/amplitude directory is a valid
directory.
storageFormats: overload eventFileWriter.addEvent() more sensibly

rework the overloading of the eventFileWriter.addEvent method in a more
sensible way. Edit in a way so the convertion from vector to TClonesArray only
happens one time, not from ClonesArray to vector and back to ClonesArray.
not ready: calcAmplitudes