hideHeader misplacement bug fixed
Performance improvement
#1815
#2117
Merge pull request #2212 from jpuri/master

#1815
fix for move column issue
Merge pull request #2258 from jpuri/master

fix for move column issue
chore(allFeatures) Add column moving to all Features tutorial
fix(cellNav): Don't setup when directive not there

The cellNav feature was attaching logic to render containers and grid
cells despite the uiGridCellnav directive not being on the parent grid
component. This was causing exception to be thrown during scroll events.

This change looks for the cellNav controller (which is simply
empty) and bails before attaching logic if the controller is not present.

Also added tests to cover the exceptions that were occuring.

Fixes #2128
Merge branch 'hideHeaderBug' of https://github.com/mathiasdose/ng-grid into mathiasdose-hideHeaderBug

Conflicts:
	src/js/core/factories/GridOptions.js
fix(Header): Hidden header height misplacement

A hidden header caused the scrollbar and viewport to be drawn lower and
smaller than they should have been.

Fixes #1995

BREAKING CHANGE: The `hideHeader` option has been changed to `showHeader`

To migrate, change your code from the following:

`hideHeader: true`

To:

`showHeader: false`
fix(Pinning): Add left border for right container

There was a border on the left container but not on the right container;
no visual separation.
partial fix for issue #2261
Merge pull request #2262 from jpuri/master

partial fix for issue #2261
refactor(Aggregation): Use local function

The function was always iterating all rows and saving the results on a local variable to be used in only 4/6 of the time, causing a lot of overhead.

Its now wrapped in a local function and is called only when needed.
docs(GridApi) Improve docs and add example on how to subscribe to events
Enh(headers): add sectionHeaders grid option for enabling section headers
Enh(headers): add getSectionWidth method for section header rendering
Enh(headers): add template for recursively rendering section headers