fix bugs etc for 2.2.9

Zoom bounds not respected on pinch #598
Improve thresholds of three finger swipe box select #596
Edge selected on touchmove pan #601
iPhone bottom browser bar disturbs position offsets on docs #595
Drag layer elements not cleared on pinch #594
Extensions download on main docs page #590
Clarification of ready event #591
build docs for 2.2.9 release testing
demo screenshots active
prepare for 2.2.9 release
fix pkgver
rebuild w/ pkgver
improved main example & demos css for small screens
remove user demos (we have the demo list now)
better scaling of demo imgs
cy.center( eles ) and cy.center( selector ) does not work #603
docs should have container info
cy.resize() needed when showing cy after hide for demo
notes on builds & branches
Fix element JSON example #627
linting
prepare 2.2.10 release
leaner packages for bower & npm
docs updates

Detailed compound node description in documentation #629
arch typo
Merge remote-tracking branch 'origin/master' into graphical-annotations