bump glog version from 0.3.5 to 0.4.0

Tested by building another package which depends on glog and verify that
it builds successfully.

Signed-off-by: Amol Bhave <ambhave@fb.com>

ac_cv_header_libunwind_h needs to be set to 0, as ac_cv_have_libunwind_h
overwritten based on the former's value.

Signed-off-by: Eneas U de Queiroz <cote2004-github@yahoo.com>

Switched to codeload and updated Makefile for consistency between projects

Signed-off-by: Rosen Penev <rosenp@gmail.com>

glog is C++ implementation of the Google logging module

Signed-off-by: Amir Sabbaghi <asaba90@gmail.com>