Implemented optional modular build:
- triggered with ALICEO2_MODULAR_BUILD option
- does not require the environment variables SIMPATH and FAIRROOTPATH
Conflicts:
	devices/aliceHLTwrapper/CMakeLists.txt
Migration of MC related classes for multi-threading & code cleanup:
- Use of RootManager and Logger (not yet ported) inactivated on workers
- Removed unused AliceO2::Base::Module class
adding a helper which implements HLT data format functionality, originally implemented in Component class
using MessageFormat class for the input message processing
implementing the output functionality in the MessageFormat handler and using it from the component; this fixes also the data corruption problem as the buffers are now separated
o2cdb: namespaces, naming, format, first doxygen

Importing STEER/CDB/ from AliRoot as starting point of the o2cdb,
applying naming conventions to it.
Get rid of cmake warning due to missing space in CMakeLists.txt

Apply clang format on o2cdb

Format function names.
The camelcase convention with lowercase starting letter has been
abandoned for compatibility with ROOT in the following cases:
GetName (for TObject derived)
Compare and IsSortable, for allowing TList,TClonesArray::Sort
XmlHandler::On* methods, for compatibility with TXMLParser

Remove hardcoded storage uris for DataType

First doxygen (Entry) and removing //______

Rename Entry as Condition
Entry,ObjectId,MetaData->Condition
<Local|Grid|File>Storage
Path -> IdPath
RunRange -> IdRunRange

Introduce a FairMQ server and client
Exclude Client/Server from dictionaries generation