[dev-qt/*] Bump Qt5 to 5.3.1

Based on 5.3.* ebuilds. In most cases 5.3.0 and 5.3.9999 are the exact sames. Only the following three cases did need extra review:

`dev-qt/qtcore`: Dropped patches as they are merged upstream.
`dev-qt/qtwebsocket`: Kept patch as it is not merged into the 5.3 series
`dev-qt/qtwidgets`: Dropped patches as they are merged upstream.