Merge aku's changes (slightly stale)
Merge aku's changes again
Merged kbk-extras into development branch at aku's request
Moved the M_PI portability definition from its location in crimp.tcl into a more generally accessible header file (util.h). Fixed gauss.c windows issues with M_PI by including util.h
Fix portability issue with the inline qualifier. MSVC uses a different keyworkd, __inline
Fix typo in commit [9e3ea9e26b]. Now we only have link errors from c/gauss.c
Added checks for the existence of various float-math functions and
delegates them to their double counterpart of the compiler doesn't
provide them.

This replaces rev [1a2b5e973a] (moved to a mistake branch), and
reverts part of rev [2e4a6fce26].

This change relies on functionality provided by critcl in rev
[8299af2478] and forward.
Merged the latests merges (kbk-extras) and fixes from work-for-critcl-2.1.
Convert puts left by merge into critcl::msg, and noted where we could provide messaging about the operators compiled inot the library.
Added a demonstration of a magnifier following the mouse when over the shown image. Not perfect at the borders. This is something which I should add to the framework, so that it can be used to look at the output of any demo. Another obvious extension would be to multiple settings (currently fixed to 8x of a 20x20 region)
Refactored the magnifier demo and made it work properly at the image borders, and outside.
Fix of demos framework. Stop current demo before reloading.
Fixed off guard conditions, a copypasta bug, and dropped the now superfluous helper variables px/py.
Extended magnifier with multiple zom seetings, switchable via left/right mouse
Removed magnifier demonstration, and re-implemented as part of the demo framework, for use with all demos.
disabling inline for AIX. Its native cc seems to expect a different syntax and chokes.
Pulled the magnifier updates and AIX fix over.
Modified brew application. Ensure that no leftover BUILD can interfere with the current one.
edge_detection_changed_as_suggested_by_andreas
wiener_filter_plus_images