API v2 is not finished and should only be optionnal. Move the binary as
api-v2 and remove the dep on pecan, only use it for tests.
This also fixes bug #1092227.
Change-Id: Ifaf0ad3918460bc2107e1563f0539695467a1856
Signed-off-by: Julien Danjou <julien@danjou.info>