Turned off by default on PCs with memory > 4G; Force turned on PCs with memory < 1G.
- enhancement: add "goto block start"/"goto block end" in "Code" menu
- enhancement: add option "hide symbols start with underscore" and "hide synbols start with two underscore"
- fix: can't rename project files that not openned in editor
- fix: dpi changes in CPU window shouldn't affect main window