Merge pull request #29 from ariutta/master

merge in changes from master
Merge branch 'gh-pages' of github.com:ariutta/svg-pan-zoom into gh-pages
Merge branch 'master' into gh-pages
Merge branch 'master' into gh-pages
Merge branch 'master' into gh-pages
cache updated pan coordinates in SvgPanZoom.prototype.zoomAtPoint
Merge pull request #56 from Frencil/fix_zoomAtPoint_pan

cache updated pan coordinates in SvgPanZoom.prototype.zoomAtPoint
If new zoom is out of set bounds, zoom to the min/max bound value. Closes #57"
build
go back to viewport as id instead of class
merge in bumbu's changes
remove .orig files, add them to ignore
Add AMD/CMD module definition

Besides of AMD/CMD definition module is exposed globaly into the window.
This is done because when module is used in browser module.exports is
available so module thinks that it is required through require method.
Added temporary solution for handling IE and markers.
Rework UMD. Related to #58
Fix issue with markers and zooming in IE. Make controls work if they are enabled, regardless of zoomEnabled option value
Merge branch 'master' into gh-pages