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/Makefile

@@ -110,7 +110,7 @@ tarball:
 	@cp -r lib $(TARNAME)
 	@cp -r libtcc $(TARNAME)
 	@cp -r tools $(TARNAME)
-	@cp -r vs2015 $(TARNAME)
+#	 @cp -r vs2015 $(TARNAME)
 	@cp -r build-tcc.bat $(TARNAME)
 	@cp -r i386-win32-tcc.exe $(TARNAME)
 	@cp -r libtcc.def $(TARNAME)