Log Message:
Update to 0.5.1

Changelog:
0.5.1

  * Fixed a crash when server response did not contain cmis:baseTypeId
    property (tdf#90351)
  * Removed the requirement for non-empty password when using HTTP
    authentication credentials
  * Fixed build with boost 1.60 and gcc 5
  * Fixed a few problems found by Coverity
  * Fixed a busload of memory leaks