Create templated version for reading aligned/unaligned data from a buffer

Currently there are several different methods for reading different size primiteve data types from the given buffer. The differences with these methods are only the thrown exception type. All these functions should be unified to some generic utility functionality.

Biggest culprits are QSafeByteArray, QSafeEvent, QSafeXXXReaders and QSafeFont, as well as some other places.