Fix hang on screencast
Commit 1: revert 1fd1c037, because it can make KWin freeze
Commit 2: Only make the context current in response to a cursor move, and also only if there is not already a context current
Commit 1: revert 1fd1c037, because it can make KWin freeze
Commit 2: Only make the context current in response to a cursor move, and also only if there is not already a context current