TSLint formatter: checkstyle

Formats errors as through they were Checkstyle output.

Imitates the XMLLogger from Checkstyle 4.3. All failures have the ‘warning’ severity.

Sample Output

<?xml version="1.0" encoding="utf-8"?> <checkstyle version="4.3"> <file name="myFile.ts"> <error line="1" column="14" severity="warning" message="Missing semicolon" source="failure.tslint.semicolon" /> </file> </checkstyle>