9bff03fd3b
As explained in issue #1844 and in issue https://github.com/webpack/webpack/issues/15007#issuecomment-996615250, the way we used the `browser`-field was wrong. The main reason for using the `browser`-field is the requirement of `require('fs')` in the main-entry-file. The workaround for this was using `require('handlebars/lib/handlebars')`, but now it will also work via `require('handlebars')` for bundlers that respect the `browser`-field. The `"./runtime"`-config was removed, because it didn't have any effect. In order to detect regressions, the webpack-integration test was extended to test with different webpack versions. Fixes #1174 Closes #1844