[Review] Request from 'aduffeck' @ 'SUSE/machinery/review_141016_refuse_to_run_on_incompatible_hosts'

Please review the following changes:
  * 30742e9 Refactor OsInspector
  * a691adf System#cat_file -> #read_file, make it os agnostic on local systems
  * 8749dc4 Abort Machinery when we're running on an incompatible host
  * 1c97942 Add helper method which ensures that we're running on a compatible host
  * 1ba4efc Make specific os detection methods private, introduce "#get_os" instead
  * 07942d1 Mention supported operating system in README
  * e215d14 Merge pull request #324 from SUSE/apply_ignore_list_to_remote_dirs
  * 4ce2789 Merge pull request #323 from SUSE/review_141016_make_hound_less_strict
  * 6aac99a Apply ignore list to remote dirs
  * 38c40c7 Make hound less strict with line length, disable block check in /spec
  * 4e9d63f Merge pull request #321 from SUSE/basic_work_flow_example2
  * 00c1d74 Update man README about correct path to the main man page file
  * 531a3af Remove the generated man page part machinery_main.1.md
  * 17e3d86 Basic workflow example in man page
Unused method argument - `options`. If it's necessary, use `_` or `_options` as an argument name to indicate that it won't be used.