protos: Remove several unused macros, functions and global variables

[stweil]

The unused global variable TrainingData used a lot of runtime memory.

Signed-off-by: Stefan Weil [email protected]

[stweil]

The 2nd commit removes the unused config variable MicroFeatures. Is this acceptable, although in theory it might cause problems when it is still in use somewhere?

[stweil]

Comparing sizes before and after these commits:

   text	   data	    bss	    dec	    hex	filename
2542223	  16064	2770240	5328527	 514e8f	tesseract (old)
2540439	  16056	 410944	2967439	 2d478f	tesseract (new)

Tesseract was built with --disable-shared.

[zdenop]

I did not find any usage (yet ;-) ) Let's try it :-)