update Seafile client bundle to 6.0.6

Ports affected:
net-mgmt/seafile-client, net-mgmt/ccnet-client, net-mgmt/seafile-gui

• Updated to 6.0.6
• Added Makefile.include to update version
• Added target makesum-all for bundle
  • Sort files by numbers if numbers contained in the file name, so "1, 10, 2, 11, 3" will be sorted as "1, 2, 3, 10, 11".
  • Use native system window for Seafile main windown and cloud file browser window.
  • Fix progress overflow when uploading large file using cloud file browser
  • Improve the tip when removing an account in the client
  • Don't show download button when select folders in cloud file browser
  • Clean cache data of cloud file browser when logout an account or restart the client
  • [fix] Fix display problem for high screen Windows in win10
  • [fix] Fix libssl compatibility problem in Debain Stretch
  • Add auto-update check

PR: 219577
Submitted by: ultima1252@gmail.com (maintainer)