Improve clarity of line and branch coverage format.

- Put percentage first and then covered and total counts in brackets afterwards. Percentage is most critical at a quick glance.

- Put line and brnach coverage on separate lines.

Now it shows in a clean format, including covered branches, total branches and percent of covered branches. Something like this:

```
Coverage report generated for (1/10), (10/10), (2/10), (3/10), (4/10), (5/10), (6/10), (7/10), (8/10), (9/10) to /Users/me/Development/cntral/coverage.
Line Coverage: 58.44% (7554 / 12927)
Branch Coverage: 50.43% (1868 / 3704)
```

When branch coverage is not enabled it simply omits that line, so it appears like this:

```
Coverage report generated for (1/10), (10/10), (2/10), (3/10), (4/10), (5/10), (6/10), (7/10), (8/10), (9/10) to /Users/me/Development/cntral/coverage.
Line Coverage: 58.44% (7554 / 12927)
```

lib/simplecov-html.rb

@@ -38,9 +38,10 @@ def format(result)
       end
 
       def output_message(result)
-        str = "Coverage report generated for #{result.command_name} to #{output_path}. #{result.covered_lines} / #{result.total_lines} LOC (#{result.covered_percent.round(2)}%) covered."
-        str += " #{result.covered_branches} / #{result.total_branches} branches (#{result.coverage_statistics[:branch].percent.round(2)}%) covered." if branchable_result?
-        str
+        output = "Coverage report generated for #{result.command_name} to #{output_path}."
+        output += "\nLine Coverage: #{result.covered_percent.round(2)}% (#{result.covered_lines} / #{result.total_lines})"
+        output += "\nBranch Coverage: #{result.coverage_statistics[:branch].percent.round(2)}% (#{result.covered_branches} / #{result.total_branches})" if branchable_result?
+        output
       end
 
       def branchable_result?