New build of browsers for Win2000 (20180718)

New Pale Moon 26.5 for Win2000 build:

updated test binary:
https://o.rths.cf/gpc/files1.rt/palemoon-26.5.0-20180718.win2000.7z

and updated test binary of K-Meleon 74 with Goanna 2.2(palemoon-26.5) that works in Win2000:
https://o.rths.cf/gpc/files1.rt/KM74-g22-20180718.win2000.7z

base repo: https://github.com/roytam1/palemoon26/tree/oldvc

Changes since last build:
- SList: replace KEx version with MSPS (MIT license) portable version (c6bfbd135)
- nsNativeThemeWin: check nsUXThemeData::drawThemeEdge pointer before use (0dbac0169)

* 2018-07-26 Updated: fixed PE header version check, should work in Retail version of win2000 now.