[BREAKING CHANGE] Rename *Menu and *MenuItem widgets

Rename *Menu and *MenuItem widgets to *MenuSelect and *MenuOption.

This makes the inheritance chain clearer and avoids re-using "item",
which is already used in the context of group/item. It's especially
confusing that OptionWidget is a special kind of ItemWidget and
MenuItemWidget is a special kind of OptionWidget, but the meaning of
"Item" in MenuItemWidget is not the same as ItemWidget.

This commit was generated by running this script:
https://gist.github.com/trevorparscal/157656e75cd77cc93170

File name changes:

Scripts (src/widgets)
- TextInputMenuWidget.js → TextInputMenuSelectWidget.js
- MenuWidget.js → MenuSelectWidget.js
- MenuItemWidget.js → MenuOptionWidget.js
- MenuSectionItemWidget.js → MenuSectionOptionWidget.js
- OutlineWidget.js → OutlineSelectWidget.js
- OutlineItemWidget.js → OutlineOptionWidget.js

Styles (src/styles/widgets)
- TextInputMenuWidget.less → TextInputMenuSelectWidget.less
- MenuWidget.less → MenuSelectWidget.less
- MenuItemWidget.less → MenuOptionWidget.less
- MenuSectionItemWidget.less → MenuSectionOptionWidget.less
- OutlineWidget.less → OutlineSelectWidget.less
- OutlineItemWidget.less → OutlineOptionWidget.less

File content changes:

Scripts (*.js)
- TextInputMenuWidget → TextInputMenuSelectWidget
- MenuWidget → MenuSelectWidget
- MenuItemWidget → MenuOptionWidget
- MenuSectionItemWidget → MenuSectionOptionWidget
- OutlineWidget → OutlineSelectWidget
- OutlineItemWidget → OutlineOptionWidget

Styles (*.less)
- textInputMenuWidget → textInputMenuSelectWidget
- menuWidget → menuSelectWidget
- menuItemWidget → menuOptionWidget
- menuSectionItemWidget → menuSectionOptionWidget
- outlineWidget → outlineSelectWidget
- outlineItemWidget → outlineOptionWidget

Change-Id: I98b15437bf849bb0363229098b55d4d827ae1548
Merge "[BREAKING CHANGE] Rename *Menu and *MenuItem widgets"