Provide warning when using styles containing a semicolon

[mzabriskie]

Closes #2862

[zpao]

Awesome! A few comments incoming, but overall it looks good.

[zpao]

I think we can leave out the parens since we're not using that matching group anywhere. But good call on making the regex a bit more robust with the space checks.

[zpao]

I know you're just copying the pattern from above, but let's make use of %s instead of doing the concats (we're going to fix the others up in #2941)

[mzabriskie]

How should this be handled if the message itself is > 80 max-len? Ok to concatenate actual message to avoid lint failures?

warning(
  false,
  'Style property values shouldn\'t contain a semicolon. ' +
  'Try "%s: %s" instead.',
  name,
  value.replace(badStyleValueWithSemicolonPattern, '')
);

[zpao]

Awesome, thanks! I think this will be helpful.