Update Graticule.js

Add support for computing the height as a factor of the width.  This allows making the grid more regular in specific regions of some projections.  Also, add ability to specify grid widths and heights independently.   This allows matching externally-defined grid systems.
Merge pull request #1319 from dr-jts/patch-1

Update Graticule.js
Add missing Text Symbolizer API properties

The properties fontStyle, fontColor, fontOpacity are provided and probably should be in the documentation.
Merge pull request #1320 from dr-jts/patch-1

Add missing Text Symbolizer API properties