update getnetworkinfo help with subversion

- add missing subversion field to getnetworkinfo help
- fix style and format errors in help string
- remove unneeded int casts
Merge pull request #4982

b5ec5fe update getnetworkinfo help with subversion (Philip Kaufmann)
travis: add non-default shell testing to travis.
Bugfix: Replace bashisms with standard sh to fix build on non-BASH systems
Bugfix: Replace bashisms with standard sh in gitian descriptors
Bugfix: Replace bashisms with standard sh in tests/tools