Add vscode files so we can build/debug/test from inside the vscode ide (#513)

The new `Java.Interop.code-workspace` and related `.vscode/*`
files will improve the experience of developers to opening the root
folder of a Java.Interop checkout within VSCode.

The following Tasks are provided for VSCode use:

  * `Build Java.Interop`: Builds `Java.Interop.sln`

  * `Clean Java.Interop`: Cleans `Java.Interop.sln`

  * `Build Generator`: Builds `tools/generator/generator.sln`

  * `Clean Generator`: Cleans `tools/generator/generator.sln`

  * `Run Generator Unit Tests`: Runs the `NUnitTests` target on
    `tools/generator/generator.sln`

Unit tests can then be run and debugged if the
[xunit-test-adapter][0] extension is installed.

[0]: https://marketplace.visualstudio.com/items?itemName=wghats.vscode-nxunit-test-adapter

.vscode/extensions.json

@@ -0,0 +1,9 @@
+{
+    "recommendations": [
+      "ms-vscode.csharp",
+      "ms-vscode.cpptools",
+      "ms-vscode.mono-debug",
+      "wghats.vscode-nxunit-test-adapter",
+      "visualstudioexptteam.vscodeintellicode",
+    ]
+}

.vscode/launch.json

@@ -0,0 +1,22 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Launch",
+            "type": "mono",
+            "request": "launch",
+            "program": "${workspaceRoot}/packages/NUnit.ConsoleRunner.3.9.0/tools/nunit3-console.exe ${workspaceRoot}/bin/TestDebug/generator-Tests.dll",
+            "cwd": "${workspaceRoot}bin/TestDebug/"
+        },
+        {
+            "name": "Attach",
+            "type": "mono",
+            "request": "attach",
+            "address": "localhost",
+            "port": 55555
+        }
+    ]
+}

.vscode/settings.json

@@ -0,0 +1,10 @@
+{
+    "nxunitExplorer.nunit": "packages/NUnit.ConsoleRunner.3.9.0/tools/nunit3-console.exe",
+    "nxunitExplorer.modules": [
+        "bin/TestDebug/generator-Tests.dll",
+        "bin/TestDebug/Java.Interop.Tools.JavaCallableWrappers-Tests.dll",
+        "bin/TestDebug/LogcatParse-Tests.dll",
+        "bin/TestDebug/Xamarin.Android.Tools.ApiXmlAdjuster-Tests.dll",
+        "bin/TestDebug/Xamarin.Android.Tools.Bytecode-Tests.dll",
+    ]
+}

.vscode/tasks.json

@@ -0,0 +1,67 @@
+{
+    // See https://go.microsoft.com/fwlink/?LinkId=733558
+    // for the documentation about the tasks.json format
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "label": "Build Java.Interop",
+            "type": "shell",
+            "command": "msbuild Java.Interop.sln /restore /t:Build",
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            },
+            "problemMatcher": [
+                "$msCompile"
+            ]
+        },
+        {
+            "label": "Clean Java.Interop",
+            "type": "shell",
+            "command": "msbuild Java.Interop.sln /restore /t:Clean",
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            },
+            "problemMatcher": [
+                "$msCompile"
+            ]
+        },
+        {
+            "label": "Build Generator",
+            "type": "shell",
+            "command": "msbuild tools/generator/generator.sln /restore /t:Build",
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            },
+            "problemMatcher": [
+                "$msCompile"
+            ]
+        },
+        {
+            "label": "Clean Generator",
+            "type": "shell",
+            "command": "msbuild tools/generator/generator.sln /restore /t:Clean",
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            },
+            "problemMatcher": [
+                "$msCompile"
+            ]
+        },
+        {
+            "label": "Run Generator Unit Tests",
+            "type": "shell",
+            "command": "msbuild tools/generator/generator.sln /restore /t:RunNunitTests",
+            "group": {
+                "kind": "test",
+                "isDefault": true
+            },
+            "problemMatcher": [
+                "$msCompile"
+            ]
+        }
+    ]
+}

Java.Interop.code-workspace

@@ -0,0 +1,8 @@
+{
+ 	"folders": [
+ 		{
+ 			"path": "."
+ 		}
+ 	],
+ 	"settings": {}
+ }