1.1.0

This is the first development release leading towards the 1.2 series.

• Use the new libwpe API to notify when frames have been displayed (#28).
• Allow calling wpe_fdo_initialize_for_egl_display() multiple times, with a warning printed to the standard error output when trying to switch displays (which is unsupported) (#26).
• Provide a dummy implementation of the EGL offscreen target interface, to let WebKit use Pbuffer-based offscreen contexts as fallback, instead of crashing (5a4b58c).
• Minor cleanups in headers and function prototypes (#25, #24).