Define at least one virtual method in polymorphic class cpp files to
improve link efficiency. Do so by defining a defaulted destructor or
another overridden virtual method in the class cpp file.
Also add explicitly defaulted copy/move constructors and assignment
operators to follow the rule of five and to avoid compiler suppression
of these functions due to the addition of a user-provided destructor.
Where neccessary, create new cpp files and add them to CMakeLists and
Testing.cmake. Set the -Wweak-vtables by default when compiling with
clang to issue warnings for new classes that do not comply with this
pattern.
See http://llvm.org/docs/CodingStandards.html#provide-a-virtual-method-anchor-for-classes-in-headers.
Fixes#6036.
v0.0.2 of toxext_extended_messages brought in a user configurable max
message size. This changeset implements the minimum work required for
qTox to work sanely under the new API.
* Hardcode a max message size for all friends
* If a friend negotiates a max message size below the hardcoded value
pretend they do not have the extension
* Move splitMessage out of Core to MessageProcessor
* Updates to allow for extended messages to be split
Don't add Wzero-as-null-pointer-constant by default, since on older Qt
versions that we stil support and that our CI runs agains, Qt API themselves
cause warnings which lead to build errors all over the place.
Fix#6008
