Share debuggees between debugger implementations
There's been lots of duplicated code since the merge of the LLDB plugin
work to kdevelop.git master. All the debuggees have been duplicated
since.
This patch fixes this, and moves the debuggees to a common directory
where both the GDB + LLDB plugin can use them.
Also rename qtprinters -> test_gdbprinters.
Next task: Fixing those unit tests...