Fixes for windows

[pecheny]

#44 related. As for building on windows, I have following results:

1. Sample project builds and runs fine (hl target) with batch scripts. Call under vcvars and make sure %HLPATH% is set and point to folder with hl. (1.10 in my case it's last 32 bit release).
2. Test launcher for windows (test-windows.bat ) do what it should – builds and calls tests.
   2.1 test under hl fails with
   src\module.c(465) : FATAL ERROR : Invalid signature for function ammer_native@w__ammer_externs_AmmerArray_0_AmmerArray_0_ofNativeInt : POBi__Xwt_array_0_0_ required but POiBi__Xwt_array_0_0_ found in hdll
   2.2 Linking cpp test fails with
   native.obj : error LNK2019: unresolved external symbol _utf8_decode referenced in function _rev_string
   But if body of rev_string() in native.c is commented out then 171 out of 173 assertion is succeeded.
   2.3 Test on eval fails with exception Ammer.hx:572: characters 13-18 : Uncaught exception !
3. the PR is also contains fix for MSVC compiler flags.

[Aurel300]

Thanks!