More backend changes.

- Update .gitignore

- Adjust BUILDING.rst

- Import LaTeX docs and delete compiled PDF and old HTML docs.

- Add build_pass scope to dwarftherapist.pro.

- Modify attributes to use ATTRIBUTES_TYPE enum instead of ints and
  casts.

- Fix vector enumeration memory leak.

- Move OSX authorization to subclass.

- Remove unused code from utils.h, add quint64 support to hexify.

- Remove useless concurrency that blocked the main thread anyways.

- Modify DFInstanceLinux to move out process_vm logic to separate
  function and use syscall() instead of glibc wrappers; this way, they
  will work regardless of glibc version.

- Rewrite DFInstanceLinux::write_raw_ptrace to only read excess data
  instead of the entire write.

- Fix various windeployqt.sh issues.
Use QDir::search_paths &c instead of find_files_list.

Also, obey CXX if set.