Added wrapped line syntax to structure.rst. Updated wrapped lines in functions.rst to match
Removed notes on color syntax from recode, categorize and interpolate functions
Changed tutorial order to polygon, line, point, raster for better complexity ramp/user experience
Changed Colors 6 and 7 in YSLD tutorial to be more distinct
Changed final raster style to use ramp instead of intervals for a smoother, less pixelated look
Cleaned up point tutorial; Changed population calculation to use POP_MAX, changed basic point style from yellow to orange, increased size of large scale point style
Added x-labelPriority to text symbolizer reference
Added ${ } to line wrap for properties
Restructured YSLD Polygon to tutorial for better complexity ramp. Introduced variables.
Minor fixes to polygon tutorial
Merge pull request #793 from tbarsballe/yslddocs

YSLD Documentation fixes