Support reading feature paths from the rerun formatter file

"@<file path>" as a feature path argument will result in that the file
<file path> is read and the content interpreted according to the
syntax created by the rerun formatter. If a feature path from the
<file path> is not found on the file system, then it will be loaded
from the classpath.
Merge branch 'read-rerun-formatter-file' of https://github.com/brasmusson/cucumber-jvm into brasmusson-read-rerun-formatter-file
Merge branch 'brasmusson-read-rerun-formatter-file'
Attribution for #726