Support attaching to running app (#85)

* add support for timeout on adb socket reads

* add debugger support for attaching to a process

* add new launch configuration and support for picking an Android process ID

* initial support for attaching to android process

* display enhanced quick pick list with pids and names

* add flag to prevent disconnect messages when not connected

* Retrieve all loaded classes during startup.
This allows us to identify breakpoints in anonymous classes that are already loaded.

* correct name of process picker command

* make PickAndroidProcess command private

* selectAndroidProcessID always returns an object

* make breakpoint setup a loop instead of recursive

* tidy some labels and error messages

* use a more consistent command for retrieving process names

* show pid list sorted by pid instead of name

* refactor some Android and ADB-specific functions
Check ANDROID_SDK as replacement for ANDROID_HOME

* tidy up logcat launch and refactor target device selection

* fix logcat not displaying

* filter duplicates and blanks from logcat output

.vscode/launch.json

@@ -14,7 +14,7 @@
             ]
         },
 		{
-			"name": "Server",
+			"name": "Debugger Server",
 			"type": "node",
 			"request": "launch",
 			"cwd": "${workspaceRoot}",
@@ -35,8 +35,8 @@
     ],
 	"compounds": [
 		{
-			"name": "Extension + Server",
-			"configurations": [ "Launch Extension", "Server" ]
+			"name": "Extension + Debugger",
+			"configurations": [ "Launch Extension", "Debugger Server" ]
 		}
 	]
 }