- Remove source URL synergy prefix

- Update to 1.8.7
- 1.8.7 changes
* Bug #5784 - Edition changes when reopening GUI
- 1.8.6 changes
* Bug #5186 - Cursor stuck on client when using multi-DPI server
* Bug #5722 - Malformed serial key in registry will crash GUI on startup
* Bug #5752 - Tab order is incorrect on Settings dialog
- 1.8.5 changes
* Bug #5680 - Server crashes when disconnecting SSL clients
* Feature #5707 - User upgrade statistics
- 1.8.4 changes
* Bug #4420 When XRandR adds a screen, it is inaccessible
* Bug #5603 Activation notification depends on existence of /etc/os-release
* Bug #5624 Update notification sometimes requests a downgrade
* Bug #5329 Current date is shown for build date in the about dialog
* Bug #5640 Synergy branding is inconsistent across platforms
* Enhancement #5617 Remove redundant plugin infrastructure
* Enhancement #5627 Move SSL certificate generation to main window
* Enhancement #5628 Move SSL implementation into core binary
* Enhancement #5629 Move activation from wizard into new dialog window
- 1.8.3 changes
* Bug #4740 - Linux client crashes with "Assertion '!m_open' failed"
* Bug #4879 - Memory leak caused by IpcReader
* Bug #5373 - Tab behaves like shift tab on client
* Bug #5502 - Copy and paste from server to client doesn't work
* Enhancement #123 - Option to disable clipboard sharing