En route to moving the title to the web view.
Added support for per-field toolbar in the web view.
Intermed. commit: moving the placeholder code to WPEditField.
Fixed placeholders.
Fixed setting a WPEditorField html to nil.
Fixed the placholder color setter.
Fixed setting the fields' html content.
Made the webview's background white.
Merge pull request #262 from wordpress-mobile/issue/170-grey-screen-rotation

Made the webview's background white.
Fixed the placeholder colors.
There's no more need to set the web view insets.
Removed class WPInsetTextField.
Removed some unnecessary headers.
Fixes the initial focus when in edit mode.
The editor height is always correct now :-).
Removed the debugging HTML colors.
Fixed editing and removing links.
Fixes the toolbar in landscape mode.
Fixed link editing for iOS 8.
Fixes a problem with the source view insets.  Fixes toolbar.