[ALOY-434] Styles in platform-specific and theme folders should be merged, not completely overwrite base styles

update (3/21/2013)

Both platform-specific styles and theme styles will now merge, not overwrite, any existing generic styles. They will merge in the following order, from lowest to highest precedence:

generic styles

theme styles

platform-specific generic styles

platform-specific theme styles

The themes test app in the github repo will be modified to show this behavior: https://github.com/appcelerator/alloy/tree/master/test/apps/advanced/themes

original

Styles housed in the platform-specific folders currently overwrite non-platform-specific styles relevant to the same runtime controller. Instead of wholely overwriting these styles, the platform-specific style should merge with any existing styles, just as it does with device queries in the TSS files themselves. This will allow developers to write more concise platform-specific styles without having to recreate the whole style.