... before any exceptions occur.

(cherry picked from commit 08da247a)

... before any exceptions occur.

Also, I made a separate macro for the current function name, which
helps simplify a lot of code that uses it.

I've left HAVE_LIBPTHREAD as a CMake variable, since TBB's build depends on it.

Some macros in internal.hpp depended on HAVE_ALLOCA_H, but they were, in turn,
unused, so I've just deleted them all.

added script to build the universal opencv2.framework for iOS device and simulator. fixed opencv_world cmake script to create static libopencv_world.a for iOS. temporarily disable compressed file storages in the case of iOS (to avoid dependency of zlib)

backported API for storing OpenCV data structures to text string and reading them back (r8481, r8516, r8518, r8522)

returned the new floating-point number formatting