Fixed problem with wrongly initialized sf::RenderStates::Default

This static variable depended on the global variable sf::BlendAlpha, which may not be constructed yet.
Removed Travis CI config.
Merge pull request #586 from LaurentGomila/feature/no_travis

Removed Travis CI config.
Fix build of the SFML target on OS X with Xcode
Removed vertical tab support from Text (#442).
Merge pull request #596 from Ceylo/bugfix/595_OSXFrameworkCreation

#595 Fix build of the SFML target on OS X with Xcode

Nevertheless, Xcode generator is not officially supported by SFML
Updated glext, removed glxext.

Removed glxext in favor of the system version.
add HTTP support for PUT and DELETE

Signed-off-by: binary1248 <binary1248@hotmail.com>
Fix the case where not having created a GlResource prior to calling Shader::isAvailable() would break context management. (#211)
Add compat report