features grouped according to render order

(not sure, whether grouping is really a good idea)
real area calculation
code reorg
CartoCSS processing for text

WIP
stroke/fill order is respecting text as well
reverting features by type
reverting features by type
CartoCSS text handling fixed - dynamic labels working
start handling CartoCSS colors for text

marker pos fix
tests fixed
context manipulation moved to renderer

example uglified :-)
cleanup
minimal example added
state per context WIP
Merge branch 'develop' into gh-pages

Conflicts:
	vecnik.debug.js