Added options for better TC reporting of npm tasks

[mheuser]

This pull request will make it able to have nicer teamcity reporting for npm test tasks (with tc reporting) since we ca now have special npm commands "RunTest" and "Test" for calling "npm run %s --silent" or "npm test --silent" which will throw a unit test exception (no tc failure reporting at the end / npm error reporting, see npm:8821).

I also added a RunSilent task to be able to fail stuff withouth the npm error output.

For (manual) testing I've also added a sample npm+grunt project, needs node installed (only tried with mono yet):

# Trick the TC detection locally
FAKE/Samples/WebNpmGrunt > export TEAMCITY_VERSION="10"

# Default Target is "Test <== Install" / There should be no tc buildStatus / npm err msg on the end of the build log
FAKE/Samples/WebNpmGrunt > mono ../../build/FAKE.exe build.fsx

# There should be no tc buildStatus / npm err msg on the end of the build log
FAKE/Samples/WebNpmGrunt > mono ../../build/FAKE.exe build.fsx RunTest

# There should be no npm err msg on the end of the build log
FAKE/Samples/WebNpmGrunt > mono ../../build/FAKE.exe build.fsx RunSilent

# Should be same as before this PR / there aare npm err msg and a buildStatus msg
FAKE/Samples/WebNpmGrunt > mono ../../build/FAKE.exe build.fsx Run

Would be nice to see this soon in master 😃 . And thanks for FAKE 🙌 !

[forki]

Thanks!