fix handling of colorbars in R2014b

* E.g., testcase 96 `colorbarLabelTitle` failed due to the colorbar being filtered in R2014b
* The filter was extended to properly handle colorbars in R2014b
* Comments were updated a little bit
remove duplicate check for colorbars
use TikZ default style for 'dash-dot line'

* MATLAB: LineSpec
* PGFplots: Chapter 4.7.2 Line Styles
Merge pull request #490 from PeterPablo/improve_linestyle

use TikZ default style for 'dash-dot line'

Inspected visually.
Merge pull request #488 from PeterPablo/fix_R2014b_colorbar

fix handling of colorbars in R2014b