Improve the "Edit Environment Variable" dialog box to be functionally as similar to the one of Windows 10.
CORE-11733
- Improved the existing dialog box. In particular, allow it to be resizable.
- Implemented new "fancy" dialog box for variables containing multiple directories as values,
showing them in a list.
There is no need to compile our DLLs as shared libraries since we are
managing symbols exports and imports through spec files.
On my system, this reduces the configure-time by a factor of two.
