surefire: Use forkCount instead of deprecated forkMode.

Additionally use a property `surefire.forkCount` for this, so creation
of coverage reports may be triggered by running:

```
mvn clean test jacoco:report -Dsurefire.forkCount=1
```
Refactor parsing to a method object, to make the flow clearer.
Rename NetRcParser to NetRc as suggested in #4.
Reorder imports.
Merge pull request #5 from mfriedenhagen/forkCount

surefire: Use forkCount instead of deprecated forkMode.
Merge pull request #6 from mfriedenhagen/netrc-refactor

NetRc refactor and rename
netrc support for SshNodes as well
sshnode: added support for username/password authentication
cleanup netrc construction and exception handling; don't try to be a netrc fassade