updates & cleanups (tcc-doc/Changelog/TODO ...)

- tcc-doc.texi: commandline option info update
- Changelog/TODO: update
- tests/tcctest.py: removed
- tests/Makefile: weaktest fixed
- tests/tests2: some files renamed and/or converted to unix LF
- configure/Makefile: --enable-static option (no dll on win32)
- win32/build-tcc.bat: msvc support
- win32/tcc-win32.txt: build info update
- win32/vs2015/: VS solution removed
- win32/include/tcc/tcc_libm.h: #include statement fixed
- tcc.c: -include <file> option help info
- .gitignore: cleanup

win32/include/tcc/tcc_libm.h

@@ -1,7 +1,7 @@
 #ifndef _TCC_LIBM_H_
 #define _TCC_LIBM_H_
 
-#include "../include/math.h"
+#include "../math.h"
 
 /* TCC uses 8 bytes for double and long double, so effectively the l variants
  * are never used. For now, they just run the normal (double) variant.