Make the popover resizable

Move the clippingView inside the background view and update it when
necessary.
Add some space around the pipe
Add a comment about rbl_clippingView
Merge pull request #122 from github/resizable-popover

Make RBLPopover resizable
Add a demo app for RBLPopover
Add missing file
Remove test target from RBLPopoverDemo
Merge pull request #123 from github/popover-demo

Add a demo app for RBLPopover
Add arrowSize to the RBLPopover demo
Merge pull request #124 from github/popover-demo-arrow-size

Add arrowSize to the RBLPopover demo
Revert #95
++xcconfigs for Xc5/5.1 build compatibility.
Merge pull request #126 from github/xcconfigs-bump

Bump xcconfigs for Xcode 5 and Xcode 5.1 compatibility.
Merge pull request #125 from github/semi-transient-nspopovers

Revert #95
Don't call -layoutSubtreeIfNeeded

Evidently it turns on Auto Layout, which may not be wanted. While this
was necessary to work with Auto Layout before, it’s no longer necessary
because the popover resizes correctly after #122.
Merge pull request #127 from github/say-no-to-autolayout

Don't call -layoutSubtreeIfNeeded in RBLPopover
Add a workspace for standalone development.
Pull dependencies from the workspace.
Add an anchor point to RBLPopover
Add the anchor point to RBLPopoverDemo