added powershell clone scripts

.gitignore

@@ -0,0 +1,2 @@
+.drone.jsonnet
+.drone.jsonnet.yml

windows/clone-commit.ps1

@@ -0,0 +1,13 @@
+
+Set-Variable -Name "FLAGS" -Value ""
+if ($Env:PLUGIN_DEPTH) {
+    Set-Variable -Name "FLAGS" -Value "--depth=$Env:PLUGIN_DEPTH" 
+}
+
+if (!(Test-Path .git)) {
+	git init
+	git remote add origin $Env:DRONE_REMOTE_URL
+}
+
+git fetch $FLAGS origin "+refs/heads/${Env:DRONE_COMMIT_BRANCH}:"
+git checkout $Env:DRONE_COMMIT_SHA -b $Env:DRONE_COMMIT_BRANCH

windows/clone-pull-request.ps1

@@ -0,0 +1,16 @@
+
+Set-Variable -Name "FLAGS" -Value ""
+if ($Env:PLUGIN_DEPTH) {
+    Set-Variable -Name "FLAGS" -Value "--depth=$Env:PLUGIN_DEPTH" 
+}
+
+if (!(Test-Path .git)) {
+	git init
+	git remote add origin $Env:DRONE_REMOTE_URL
+}
+
+git fetch $FLAGS origin "+refs/heads/${Env:DRONE_COMMIT_BRANCH}:"
+git checkout $Env:DRONE_COMMIT_BRANCH
+
+git fetch origin $Env:DRONE_COMMIT_REF:
+git rebase $Env:DRONE_COMMIT_SHA

windows/clone-tag.ps1

@@ -0,0 +1,13 @@
+
+Set-Variable -Name "FLAGS" -Value ""
+if ($Env:PLUGIN_DEPTH) {
+    Set-Variable -Name "FLAGS" -Value "--depth=$Env:PLUGIN_DEPTH" 
+}
+
+if (!(Test-Path .git)) {
+	git init
+	git remote add origin $Env:DRONE_REMOTE_URL
+}
+
+git fetch $FLAGS origin "+refs/tags/${Env:DRONE_TAG}:"
+git checkout -qf FETCH_HEAD

windows/clone.ps1

@@ -0,0 +1,60 @@
+$ErrorActionPreference = 'Stop';
+
+# if the workspace is set we should make sure
+# it is the current working directory.
+
+if ($Env:DRONE_WORKSPACE) {
+    cd $Env:DRONE_WORKSPACE
+}
+
+# if the netrc enviornment variables exist, write
+# the netrc file.
+
+if ($Env:DRONE_NETRC_MACHINE) {
+
+$netrc=[string]::Format("{0}\_netrc",$Env:HOME);
+"machine $Env:CI_NETRC_MACHINE" >> $netrc;
+"login $Env:CI_NETRC_USERNAME" >> $netrc;
+"password $Env:CI_NETRC_PASSWORD" >> $netrc;
+}
+
+# configure git global behavior and parameters via the
+# following environment variables:
+
+if ($Env:PLUGIN_SKIP_VERIFY) {
+    $Env:GIT_SSL_NO_VERIFY = "true"
+}
+
+if ($Env:DRONE_COMMIT_AUTHOR_NAME) {
+    $Env:GIT_AUTHOR_NAME = $Env:DRONE_COMMIT_AUTHOR_NAME
+} else {
+    $Env:GIT_AUTHOR_NAME = "drone"
+}
+
+if ($Env:DRONE_COMMIT_AUTHOR_NAME) {
+    $Env:GIT_AUTHOR_NAME = $Env:DRONE_COMMIT_AUTHOR_NAME
+} else {
+    $Env:GIT_AUTHOR_NAME = 'drone@localhost'
+}
+
+$Env:GIT_COMMITTER_NAME  = $Env:GIT_AUTHOR_NAME
+$Env:GIT_COMMITTER_EMAIL = $Env:GIT_AUTHOR_EMAIL
+
+# invoke the sub-script based on the drone event type.
+# TODO we should ultimately look at the ref, since
+# we need something compatible with deployment events.
+
+switch ($Env:DRONE_BUILD_EVENT) {
+    "pull_request" {
+        .\clone-pull-reqest.ps1
+        break
+    }
+    "tag" {
+        .\clone-tag.ps1
+        break
+    }
+    default {
+        .\clone-commit.ps1
+        break
+    }
+}