Release 0.5.3

• Changed signature of ISurface::fill_poly, ISurface::wire_poly and ISurface::draw_poly methods.
• Added ISurface::draw method that uses ws::rectangle_t as an argument.
• Updated task scheduling interface: now the time the task has been scheduled is returned to handler.
• Fixed issues with improper font rendering and size estimation.

Release 0.5.2

• Added nPreWidth and nPreHeight to ws::size_limit_t structure which should contain
  preferred width and height values.
• Fixed uninitialized pointer dereference in X11Display.
• Updated build scripts that now use tags without prefixes first.
• Updated headers and license files to match LGPL3+ license.
• Updated make files to produce static library, pkgconf file and source tree.