CMake doesn't require absolute paths so we can safely remove
SRCROOT and let implicit relative pathing achieve the same result
with less work on our part.
This removes the sfml- prefixed targets from the export set. The sfml-
prefixed targets are still available within the build tree but not to
downstream users thus making this an API breaking change when compared
to the 2.x releases. To keep things consistent, usage of the sfml-
targets were replaced with their namespaced counterparts.
This has a number of benefits:
1. It's more idiomatic. Modern CMake libraries are expected to
have namespaced targets.
2. Namespaced targets are less likely to collide with user-defined
targets. No one will accidentally define a SFML:: target.
3. If a namespaced target is not found by CMake, configuration
will immediately stop.
* French to English punctuation.
* Pong and Shader use fixed-sized windows now (especially on tiling
window managers, the windows will be resized automatically, thus
making the examples look and also behave weirdly).
