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
Merge remote-tracking branch 'tax/master'