Merge remote-tracking branch 'upstream/master'

st commit's message is:

Wrap SIGPIPE in ifndef block for Windows

Allow Position Independent Code for Static Library (aws#73)

Build the static library with the fPIC compiler flag, so that it can be linked into a shared library.

Fix wildcard regex for special topics with $ symbols

Adding standard files (aws#83)

Pull requests to fix warnings on Windows

Includes aws#75, aws#76 and aws#77. Also includes other changes related to
- loading and storing of atomic variables
- fix for UTF-8 character representation on Windows

Update sample documentation with shadow client token limitation

Make Shadow::HandleGetResponse call response handler on Rejected response

Fixes aws#86

Make Shadow::HandleGetResponse call response handler on malformed payload

Allow Position Independent Code for Static Library (aws#73)

Build the static library with the fPIC compiler flag, so that it can be linked into a shared library.

Adding standard files (aws#83)

Pull requests to fix warnings on Windows

Includes aws#75, aws#76 and aws#77. Also includes other changes related to
- loading and storing of atomic variables
- fix for UTF-8 character representation on Windows