Fix race warning

CID 1201438
Resolve static initialization order fiasco
StatusBar: less greedy invalidation

Fixes rare flickering.
MainFrame: call OnGetMinMaxInfo() before resize
Cosmetics
SysVersion: use 'static' for local functions
WebUI: Cleanup.
WebUI: only make available to global scope the functions we need to access.
Use AtlEscapeUrl/AtlUnescapeUrl to do URL encoding/decoding.

This is now available outside of ATL Server. It avoids using our incomplete URL encoding function.
Readme.md: switch to SVG badge.