Build behind proxy and appveyor.

Fixes #79. Uses Download-File function from d654a53ec43038c42344f9cdbe0abc5b8ff9b387

Create appveyor.yml

Should send build notifications to gitter as well.

Adds appveyor build status badge.

Always compile launcher for AppVeyor

This is to catch any errors that may be caused by changes to the launcher or any outside scripts.

scripts/build.ps1

@@ -74,7 +74,7 @@ if ($config -ne "") {
     } else { $ConEmuXml = "" }
 } else { $ConEmuXml = "" }
 
-
+$vend = $pwd
 foreach ($s in $sources) {
     if($Full -eq $false -and $s.name -eq "git-for-windows"){
         Continue
@@ -87,7 +87,7 @@ foreach ($s in $sources) {
     Delete-Existing $tempArchive
     Delete-Existing $s.name
 
-    Invoke-WebRequest -Uri $s.url -OutFile $tempArchive -ErrorAction Stop
+    Download-File -Url $s.url -File $vend\$tempArchive -ErrorAction Stop
     Extract-Archive $tempArchive $s.name
 
     if ((Get-Childitem $s.name).Count -eq 1) {

scripts/utils.ps1

@@ -89,3 +89,16 @@ function Register-Cmder(){
         New-Item -Path "HKCR:\Directory\Shell\Cmder\Command" -Force -Value "`"$PathToExe`" `"$Command`" "
     }
 }
+
+function Download-File {
+    param (
+        $Url,
+        $File
+    )
+    # I think this is the problem
+    $File = $File -Replace "/", "\"
+    Write-Verbose "Downloading from $Url to $File"
+    $wc = new-object System.Net.WebClient
+    $wc.Proxy.Credentials=[System.Net.CredentialCache]::DefaultNetworkCredentials;    
+    $wc.DownloadFile($Url, $File)
+}