'Run' action

[weinand]

• OS X @sofianhn
• Linux @joaomoreno
• Windows @dbaeumer

for #2780

In addition to debugging a program, VS Code now supports to 'Run' a program. 'Run' still starts a debug session in order to reuse functionality that makes sense in both modes, e.g. the 'Stop' button to terminate the program, or the debug console. But all debug controls like 'Step' or 'Pause' buttons are disabled.

The 'Run' action is always available but it only 'runs' a program for debug extensions that support it (as of March this are 'node', 'extensionHost', and 'mono'). If 'run' mode is not supported, the 'Run' action behaviour is identical to 'Debug'.

• Verify that 'Run' works as expected for node (and mono) programs as well as extensions.
• Verify that debug functionality is disabled in 'run' mode.