- do not use gb_UnpackedTarball_copy_header_files for boost
- adapt the optimization in concat-deps.c for new path
- use boost_headers in all LinkTargets that require it
- add explicit include paths to mysqlc, mysqlcppconn, libvisio, liborcus
Change-Id: I0c43e73ed43cc9d2e6bce8faf55e992d655a0bb9
Naming convention for gbuild methods:
- "add" is used for stuff that is logically a part of the target
(i.e. not registered at the Module, but defined in the target's makefile)
- "use" is used for stuff that is logically a different target
(i.e. it is registered at the Module, has it's own makefile, may be
in a different module than the target)
