fix crash with FOLDERID_LocalAppDataLow not found

The macro DEFINE_KNOWN_FOLDER was copied from <KnownFolder.h>,
it will link FOLDERID_LocalAppDataLow to an external dll,
but for some system(to me, Windows 7, Chinese Edition), the symbol can't be found at runtime,
so FOLDERID_LocalAppDataLow becomes GUID_NULL, and at line 52, it will fail with crash.

Really strange.

Let's inspect <KnownFolder.h> again, there are two styles of DEFINE_KNOWN_FOLDER:

#ifdef INITGUID
#define DEFINE_KNOWN_FOLDER(name, l, w1, w2, b1, b2, b3, b4, b5, b6, b7, b8) \
        EXTERN_C const GUID DECLSPEC_SELECTANY name \
                = { l, w1, w2, { b1, b2,  b3,  b4,  b5,  b6,  b7,  b8 } }
#else
#define DEFINE_KNOWN_FOLDER(name, l, w1, w2, b1, b2, b3, b4, b5, b6, b7, b8) \
        EXTERN_C const GUID name
#endif // INITGUID

Shall we use the first one without `extern`?
check HRESULT after getKnownFolderPath

talked in
https://github.com/firebreath/FireBreath/pull/88
Let the unix build scripts fail on the first error.
Allow super-projects to disable firebreath-specific git operations.

Git submodule commands must be run from the toplevel of the working tree,
so this is necessary when firebreath is embedded in a git super-project
requiring the firebreath-provided boost submodule.
Remove dead code.
Fixed bug with find_x11_deps called on non-x11 platforms
FIREBREATH-213: Fix for iostreams in the wrong filter
FIREBREATH-210: add support for req.setCallback on unsolicited streams
Add log msg for unsolicited streams
Fix build warning
Replaced line that was somehow accidentally removed in commit 774c948f5e8
Merge pull request #91 from manctl/manctl-patches

Improve Firebreath embeddability.
Merge pull request #89 from asinbow/patch-2

check HRESULT after getKnownFolderPath
Merge branch 'master' of github.com:firebreath/FireBreath
FIREBREATH-214: Add setReady call back into Load and InitNew
Removed unused and unfinished JSArray to avoid confusion
FIREBREATH-211: Fixed build issue with boost/process.hpp
Add template for converting container and dictionary to VariantList and VariantMap
Update to log4cplus 1.1.0
Update to basicmediaplayer to remove a couple of warnings