Fixed a bug where 3 point bezier curves were not rendered properly.
Can render primitive wire outlines.
Linking to local version of SDL2 while the distro package is broken.
Deleted phone socket texture file.

Not using those!
Edited close_view icon a bit.
Removed debug output for Knobs.
Reworked bezier curves.

- Added some documentation to bezier.h.

- Using a recursive algorithm instead of iterative one.
  Should not be much of a performance penalty, if a small
  number of control points is used.
Can render descent sockets an wires.
Setting GL_TEXTURE_ENV_MODE to GL_REPLACE for Icon.