fixed typos in manual
updated todo
- fillbetween: fixed problems if the named paths have nodes with pins.

It should also affects paths with edges or "misleading" moveto
operations.
fill between: improved support for styles and started to handle "after path" instructions
fixed bug: some tikz keys are unsuitable for the survey phase of pgfplots

disabled name intersections and intersection segments
fillbetween + afterpaths
fixed bug: now, 'stacked ignores zero' is no longer applied to markers and error bars.
added UT
updated readme