SDDL values are not idempotent

[Andy-Adrian]

Modifies regex used to detect comments, requiring a preceding space or beginning of line.

Fixes #108

[ayohrling]

Getting the following test failures locally...

Failures:

  1) local_security_policy enable registry value policy sets the value correctly
     Failure/Error: expect(value['RestrictRemoteSAM']).to eq('O:BAG:BAD:(A;;RC;;;BA)')

       expected: "O:BAG:BAD:(A;;RC;;;BA)"
            got: nil

       (compared using ==)

     # ./spec/acceptance/suites/04_registry_values_spec.rb:33:in `block (4 levels) in <top (required)>'
     # ./spec/acceptance/suites/04_registry_values_spec.rb:31:in `each'
     # ./spec/acceptance/suites/04_registry_values_spec.rb:31:in `block (3 levels) in <top (required)>'

  2) local_security_policy disable registry value policy sets the value correctly
     Failure/Error: expect(value['RestrictRemoteSAM']).to eq('')

       expected: ""
            got: nil

       (compared using ==)

     # ./spec/acceptance/suites/04_registry_values_spec.rb:58:in `block (4 levels) in <top (required)>'
     # ./spec/acceptance/suites/04_registry_values_spec.rb:56:in `each'
     # ./spec/acceptance/suites/04_registry_values_spec.rb:56:in `block (3 levels) in <top (required)>'

Finished in 1 minute 53.64 seconds (files took 19 minutes 27 seconds to load)
21 examples, 2 failures

Failed examples:

rspec ./spec/acceptance/suites/04_registry_values_spec.rb:30 # local_security_policy enable registry value policy sets the value correctly
rspec ./spec/acceptance/suites/04_registry_values_spec.rb:55 # local_security_policy disable registry value policy sets the value correctly