several installer fixes and improvements:

- fix bug that registry uninstaller settings of the previous version are not replaced when installing new version of the same series

- avoid explicit calls of the name "FreeCAD"

- update example code and description to MSVC 2017 and FreeCAD 0.19git

src/WindowsInstaller/include/declarations.nsh

@@ -1,4 +1,4 @@
-/*
+/*
 declaration.nsh
 
 Configuration and variables of FreeCAD installer
@@ -32,8 +32,8 @@ Configuration and variables of FreeCAD installer
 !define APP_WIKI_INFO "${APP_NAME} Wiki"
 !define APP_COPYRIGHT "${APP_NAME} is Copyright © 2001-${COPYRIGHT_YEAR} by the ${APP_NAME} Team"
 
-!define APP_RUN "bin\FreeCAD.exe"
-!define BIN_FREECAD "FreeCAD.exe"
+!define APP_RUN "bin\${APP_NAME}.exe"
+!define BIN_FREECAD "${APP_NAME}.exe"
 
 !define APP_REGKEY "Software\${APP_NAME}${APP_SERIES_KEY}" # like "FreeCAD0180"
 !define APP_REGKEY_SETUP "${APP_REGKEY}\Setup"

src/WindowsInstaller/include/init.nsh

@@ -130,7 +130,10 @@ Function .onInit
    ${endif} 
   ${next}
   
-  ${if} $OldVersionNumber > ${APP_SERIES_KEY}
+  # NSIS cannot handle numbers with leading zero, thus cut it off before comparing
+  StrCpy $1 $OldVersionNumber "" 1
+  StrCpy $2 ${APP_SERIES_KEY} "" 1
+  ${if} $1 > $2
    # store the version number and reformat it temporarily for the error message
    StrCpy $R0 $OldVersionNumber
    StrCpy $OldVersionNumber $R5