Fixed issue with missing textShadow on HTML datalabels

When using the option useHTML on datalabels text-shadow was missing.
Fixed issue with Series.linkedTo not working when added in non-source order. Closes #2166.
Cleaned up mess after previous commit c25ac672
Fixed regression in IE8 where an error occured on fading out the tooltip in older jQuery versions. Closes #2161.
Improved axis line, plot line and grid line positioning so that a 2px line series along the X axis shows up as exactly 1 pixel, half inside and half outside the visible plot area. Closes #1687.
Added panning in both X and Y direction, preparation for maps.
Worked on maps. Restrain zooming to the data area to previent zooming out to blank areas or zooming out beyond full size.
Fixed issue with non-aligned axes after multiple setExtremes with internal redraws. Closes #2169.
Updated file path in study
Implemented better sharpening logic for columns and bars. Closes #1188. Closes #2091.
Added error message on adding too many ticks to an axis. Closes #2174.
Fixed regression after development