* Implementation of BVH tree for IFC files using NCollection_UBTree
* Fixes for gcc and OCCT < v6.8
* Enable BVH selection by TopoDS_Shape
* Small fixes to tree
* Merge conflicted files and other changes
* Eliminate one warning (some remain) + add tree test
* ifcgeom: Add placement_rel_to for convert()
Change geometry conversion in `convert()` for `ObjectPlacement` such
that we can stop the `PlacementRelTo()` recursion when we hit an
`ObjectPlacement` that places a certain type, e.g. a `IfcSite'.
Introduce a new IteratorSetting `SITE_LOCAL_PLACEMENT` which will be
exposed in `IfcConvert`.
* IfcConvert: Add --site-local-placement
Some IFC authoring tools may put the global origo at a large distance
away from the actual building geometry. Also, the global X- and Y-axes
may be at arbitrary angles with natural building axes. Using
--center-model or --model-offset may place the converted geometry closer
to origo, but will still use the global IFC definition of axis
directions. Also, in a scenario with multiple IFC files for one
construction site, using --center-model on each of them would not
generate consistent geometry across OBJ or DAE files.
Solve this by introducing --site-local-placement which will disregard
the ObjectPlacement at the IfcSite level.
* Preliminary MSYS2 + MinGW build scripts and instructions.
* CMakeLists.txt: MinGW tweaks, enforce C++03, suppress warnings for now.
* Fix some GCC warnings.
* Fix unused parameter warnings coming from Ifc*.h.
* Fix warning regarding unreachable code (++jt) on MSVC.
* Add IfcParse_EXPORT for IfcInvalidTokenException
* Fix potentially uninitialized pointer variables.
* Note about OpenCASCADE cyclic dependencies fix.
* GCC warning fix: don't generate 'current_enum' variable that is only set and not used for anything ever
* Work around -Wmaybe-uninitialized warnings about boost::optional constructs. Also prevent passing of negative values for --bounds.
* Remove unused variable.
* CMakeLists.txt: ENABLE_BUILD_OPTIMIZATIONS for GCC (simply enforce -03)
Thomas Krijnen