Write temporary file on bib import

This resolves an issue where the encoding somehow got lost when using
the Jabref Browser extension. It will now write a temporary file
with UTF-8 encoding rather than passing the bibtex on the commandline.

See JabRef/JabRef-Browser-Extension#274

buildres/windows/JabRefHost.ps1

@@ -38,7 +38,12 @@ try {
     #$wshell.Popup($message.Text,0,"JabRef", 0x0 + 0x30)
 
     $messageText = $message.Text.replace("`n"," ").replace("`r"," ")
-    $output = & $jabRefExe -importBibtex "$messageText" *>&1
+    $tempfile = New-TemporaryFile
+    # WriteAllLines should write the file as UTF-8 without BOM
+    # unlike Out-File which writes UTF-16 with BOM in ps5.1
+    [IO.File]::WriteAllLines($tempfile, $messageText)
+    $output = & $jabRefExe -importToOpen $tempfile *>&1
+    Remove-Item $tempfile
     #$output = "$messageText"
     #$wshell = New-Object -ComObject Wscript.Shell
     #$wshell.Popup($output,0,"JabRef", 0x0 + 0x30)