Avoid including curl.h in dialog about (including curl.h creates constraints with wxWidgets especially on Windows)

and remove duplicate code.

common/dialog_about/dialog_about.cpp

@@ -24,12 +24,16 @@
 
 
 #include <config.h>
+#include <string>
 
 // kicad_curl.h must be included before wx headers, to avoid
 // conflicts for some defines, at least on Windows
 #ifdef BUILD_GITHUB_PLUGIN
-#include <curl/curlver.h>
-#include <kicad_curl/kicad_curl.h>
+// kicad_curl.h can create conflicts for some defines, at least on Windows
+// so we are using here 2 proxy functions to know Curl version to avoid
+// including kicad_curl.h to know Curl version
+extern std::string GetKicadCurlVersion();
+extern std::string GetCurlLibVersion();
 #endif
 
 #include <boost/version.hpp>
@@ -426,7 +430,7 @@ void DIALOG_ABOUT::buildVersionInfoData( wxString& aMsg, bool aFormatHtml )
     aMsg << indent4 << wxGetLibraryVersionInfo().GetVersionString() << eol;
 
 #ifdef BUILD_GITHUB_PLUGIN
-    aMsg << indent4 << KICAD_CURL::GetVersion() << eol;
+    aMsg << indent4 << GetKicadCurlVersion() << eol;
 #endif
     aMsg << "Platform: " << wxGetOsDescription() << ", "
          << platform.GetArchName() << ", "
@@ -453,7 +457,7 @@ void DIALOG_ABOUT::buildVersionInfoData( wxString& aMsg, bool aFormatHtml )
                       << ( BOOST_VERSION % 100 ) << eol;
 
 #ifdef BUILD_GITHUB_PLUGIN
-    aMsg << indent4 << "Curl: " << LIBCURL_VERSION << eol;
+    aMsg << indent4 << "Curl: " << GetCurlLibVersion() << eol;
 #endif
 
     aMsg << indent4 << "Compiler: ";

common/kicad_curl/kicad_curl.cpp

@@ -222,3 +222,13 @@ std::string KICAD_CURL::GetSimpleVersion()
 
     return res;
 }
+
+std::string GetKicadCurlVersion()
+{
+    return KICAD_CURL::GetVersion();
+}
+
+std::string GetCurlLibVersion()
+{
+    return LIBCURL_VERSION;
+}

include/kicad_curl/kicad_curl_easy.h

@@ -26,25 +26,12 @@
 
 /*
  * KICAD_CURL_EASY.h must included before wxWidgets because on Windows,
- * wxWidgets ends up including windows.h before winsocks2.h inside curl
- * this causes build warnings
- * Because we are before wx, we must explicitly define we are building with unicode
- * wxWidgets defaults to supporting unicode now, so this should be safe.
+ * because kicad_curl.h includes curl.h, wxWidgets ends up including windows.h
+ * before winsocks2.h inside curl and this causes build warnings
  */
-#if defined(WIN32)
-    #ifndef UNICODE
-    #    define UNICODE
-    #endif
 
-    #ifndef _UNICODE
-    #    define _UNICODE
-    #endif
-#endif
-
-
-#include <string>
-#include <curl/curl.h>
 #include <kicad_curl/kicad_curl.h>
+#include <string>
 
 
 /**