Split PropertyFormat into separate linters

The `PropertyFormat` linter suffered from bugs due to the brittle regex
it employed to check the format of the property declaration. This regex
also attempted to test too much, making the error message in the event
of a lint being discovered not terribly useful.

Split out the `PropertyFormat` linter into three separate linters:

  * `SpaceAfterPropertyColon`
    Prefers `margin: 0;` instead of `margin:0;`

  * `SpaceAfterPropertyName`
    Prefers `margin: 0;` instead of `margin : 0;`

  * `TrailingSemiColonAfterProperty`
    Ensures the final property in a rule set has a trailing semi-colon

These linters are simpler thanks to the support for being able to query
source ranges on all Sass parse tree nodes, and no longer require the
use of a brittle regex.

Change-Id: I4cb1bbccca1457b65ac3d66f578d15937735a37c
Reviewed-on: https://gerrit.causes.com/30680
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane@causes.com>