[rotorcraft] fix FAILSAFE vertical setpoint

This was a regression, thx Michal for catching this!!
The vertical speed setpoint was set to 0.5m/s descent rate, but upon
guidance_v_mode_changed it was set back to zero so FAILSAFE was essentially alitude hold.
[fix][logalizer] add pcre lib to plotprofile

Seems to be needed on Ubuntu 13.04 and maybe some other configurations.
Not exactly sure why it works on most 12.04 systems without that...
[fix] circle-count without rewinding when flying in opposite direction
[ins] xsens_mtig700
[trim] rudder-trim
[typo] sweep is radians now
[fix] Yaw command was overwritten by trim.
[release] maintenance version v4.2.2
update google maps version parsing for new maps site

also set the default example version to 129
[lib/ocaml] update leap_seconds

most recent leap second was inserted on June 30, 2012 at 23:59:60 UTC
So since the gps epoch 1980 we have 16 leap seconds.
[Makefile] add pcre to jsbsim target
[nps] fix compilation on newer systems