Log Message:
libcmis: update to 0.5.2.

0.5.2

  * Fixed Google Drive login, broken by Google's new 2-page login sequence
  * Added support for Google Drive two-factor authentication
  * Fixed access to SharePoint root folder (tdf#101385)
  * Limited the maximal number of redirections to 20 (rhbz#1410197)
  * Switched library implementation to C++11 (the API remains
    C++98-compatible)
  * Fixed build with boost >= 1.68.0 (#19)
  * Fixed encoding of OAuth2 credentials
  * Dropped cppcheck run from "make check". A new "make \ 
cppcheck" target
    was created for it
  * Added proper API symbol exporting
  * Speeded up building of tests a bit
  * Fixed a few issues found by coverity and cppcheck