Windows/MSVC + OCCT 7.0.0 (#124)

* Windows/MSVC build scripts: option to build and use official Open CASCADE instead of the community edition.

* Fix C4800 warnings ("'Standard_Boolean': forcing value to bool 'true' or 'false' (performance warning)") + unnecessary integer cast.

* build-deps.cmd: fix OCCT download

* Fix MSVC linking against OCCT 7.0.0. Example executables fail still, needs research.

* occt-V7_0_0-9059ca1_CMakeLists.txt: add_definitions(-DHAVE_NO_DLL) in order to fix static linking to OCCT. Mark IfcOpenShell patches in the OCCT patch files for clarity.

* Patch OCCT in order to fix compliaction when HAVE_NO_DLL is defind. Clean up IfcOpenSHell's linker warnings by defining HAVE_NO_DLL.

* CMakeLists.txt: remove linking to the newly added OCCT libs, these are not needed when HAVE_NO_DLL is defined.

* cmake/CMakeLists.txt: make add_debug_variants() function to handle filenames/paths also. Apply the coding conventions while at it. Fixes #123.

* Patch OCCT's OpenGl_PrimitiveArray.cxx and XCAFDoc_GeomTolerance.cxx in order to fix Debug build. Do not trigger OCCT rebuild each time build-deps.cmd is ran.

* build-deps.cmd: fix OCCT file patch copy.

* Non-MSVC compiler: use -Wextra, suppress/fix -Wignored-qualifiers warnings.

* build-deps.cmd: do not check return values of copy commands as they seem not to be fully reliable.

src/ifcgeom/IfcGeomFunctions.cpp

@@ -2259,7 +2259,7 @@ bool IfcGeom::Kernel::approximate_plane_through_wire(const TopoDS_Wire& wire, gp
 	BRepTools_WireExplorer exp(wire);
 
 	for (;; exp.Next()) {
-		const bool has_more = exp.More();
+		const bool has_more = exp.More() != 0;
 		if (has_more) {
 			const TopoDS_Vertex& v = exp.CurrentVertex();
 			current = BRep_Tool::Pnt(v);