Fix README and grunt install task

We need to get grunt - and that we only get through an extra npm
install.
Fix angular to 1.2.17 for now
Clarify wording of globalSettings.alwaysDeselect
Add angular-gridster
React to grid in toBottom
Customize gridster scss
Add arethusaGrid directive
Fix angular-gridster dependencies
Start with arethusaGrid service
Add main_grid template
Add borderless depTree template
Add comments to staging2
New grid placement in aG
More grid scss
Switch to a custom fork of angular-gridster

Removes jquery-ui dependencies!
Trigger window resize on grid resize
Show resize handles in grid
Clean up third party dependencies in Gruntfile
Allow style customizations of grid items
Refactor colorizerSetting directive