[WFLY-4172] Enable the -secmgr parameter for tests if the security.manager property is defined.

I left these commits separate as they seemed to make more sense that way. I can squash them together or squash specific ones together if that seems to make more sense.

### Commit 5ddbba8664f61fbf03ec28e5b0244595a9d682b5
This is the main commit for the JIRA and simply enables the testsuite to enable the security manager by passing `-Dsecurity.manager` to the build.

Note that a dummy property is passed in the `<jboss.args/>` property defined in the parent test suite pom. If left blank system property is set to `null` which in when parsed by arquillian becomes `${jboss.args}` as that's the argument in the arquillian.xml file.

### Commit ba156ec71d49c7a4be2f300c3a7750fdc9411301
Enables the security manager extension by default for all server types.

### Commit 78c08864119321b6a9369484779f1184749316b6
Fixes some issue found with generating the permissions.xml for deployments.

### Commit 7a7fb80f2e161d8bbe2a0b72eec5a83879add051
Fixes a few issues found when running the web integration tests under the security manager.
This one could use a look as the test still fails, but I think this permissions will be needed regardless.