Set the following compiler defaults:
```
"target": "es6",
"module": "commonjs",
"moduleResolution": "node",
"sourceMap": true,
```
Which allows us to not even include a tsconfig.json file. If one is
present, `ts-node` will use its options, but the above settings will
override any settings in a local tsconfig.json file. This means if you
want full control over the target, you'll need to go back to the raw
tsc workflow where you explicitly build ahead of time.
We retain a few tests on the RunBuild plan, with `typescript` set to
false in the runtime options, but for the general case, we remove the
build steps and custom entry points for our programs.
These changes introduce a new field, `Raw`, to `diag.Message`. This
field indicates that the contents of the message are not a format string
and should not be rendered via `Sprintf` during stringification.
The plugin std{out,err} readers have been updated to use raw messages,
and the event reader in `pulumi` has been fixed s.t. it does not format
event payloads before display.
Fixes#551.
