Removing grunt map tasks

To allow for a seamless transition between Sass 3.2 and Sass 3.3 which
is required for source maps separate watch and sass tasks were used for
backwards compatibility.
Sass 3.3 will now be required to run
grunt sass:dev
Removing grunt-grunticon
Removing :map tasks from gruntfile

* origin/pr/11408:
  Removing grunt-grunticon
  Removing grunt map tasks