* [rshapes] Add `DrawEllipseLinesEx()`
Add DrawEllipseLinesEx() to the API for consistency with other shape drawing functions.
* [rshapes] Add `DrawTriangleLinesEx()`
Add DrawTriangleLinesEx() to the API for consistency with other shape drawing functions.
* [rshapes] Add `DrawCircleSectorLinesEx()`
Add DrawCircleSectorLinesEx() to the API for consistency with other shape drawing functions.
* [rshapes] Add `DrawRingLinesEx()`
Add DrawRingLinesEx() to the API for consistency with other shape drawing functions.
* [examples] Add shapes_outlines_testbed
This example stress tests the previously existing and newly added shape outline functions.
