Update submodule ecl to latest Sat May 12 20:26:28 CDT 2018

    - ecl in PX4/Firmware (f5448c2): PX4/PX4-ECL@372f9f4
    - ecl current upstream: PX4/PX4-ECL@bae4b8a
    - Changes: PX4/PX4-ECL@372f9f4...bae4b8a

    bae4b8a 2018-05-11 Bart Slinger - remove superfluous elseif (#431)
16976d3 2018-05-11 Paul Riseborough - Merge branch 'pr-ekfOptFlowFixes'
75e6590 2018-05-10 Paul Riseborough - EKF: fix bug causing height offset when GPS use stops
e8e9e34 2018-05-10 Paul Riseborough - EKF: fix bug causing height offset when GPS use stops
6cadc92 2018-05-09 Paul Riseborough - EKF: Don't reject saturated flow data when it is the only aiding source
bf902e5 2018-05-09 Paul Riseborough - EKF: Prevent flow motion check false positives
bdf5b3e 2018-05-07 Paul Riseborough - EKF: Don't assume large position uncertainty when starting optical flow nav
e26711a 2018-05-05 Paul Riseborough - EKF: relax terrain update requirements for continuing optical flow use
868bc01 2018-05-05 Paul Riseborough - EKF: Relax minimum required range finder measurement rate
02963a8 2018-05-05 Paul Riseborough - EKF: relax optical flow on ground motion checks
24b005e 2018-05-03 Paul Riseborough - EKF: range finder aiding logic fixes
0c0a660 2018-05-03 Paul Riseborough - EKF: Decouple range finder use criteria checking and selection
6708bec 2018-04-29 Paul Riseborough - EKF: Don't auto select range finder for height when on ground.
0a63052 2018-04-26 Paul Riseborough - EKF: Fix false triggering of optical flow bad motion checks
f9d4934 2018-04-19 Paul Riseborough - EKF: update comments
82de314 2018-04-18 Paul Riseborough - EKF: Don't use optical flow if GPS is good and the vehicle is not using range finder for height
389786e 2018-03-12 Paul Riseborough - EKF: Stop using EV for yaw when GPS fusion starts
4ab7823 2018-02-26 Paul Riseborough - EKF: Add persistence criteria to  GPS fail check
67d71ca 2018-02-26 Paul Riseborough - EKF: allow GPS fallback if quality bad and alternative aiding available
bd59e38 2018-02-26 Paul Riseborough - EKF: always run GPS checks
b227aca 2018-05-05 Daniel Agar - geo_lookup fix table bounds
e494a4e 2018-05-05 Daniel Agar - Jenkins set git username and email with environment variables
3639087 2018-05-05 Daniel Agar - cmake and Jenkins add basic address santiizer test buld
1fba622 2018-05-05 Daniel Agar - travis-ci basic build script
cde2ee9 2018-05-05 Daniel Agar - cmake ignore missing-field-initializers
2100127 2018-05-05 Daniel Agar - geo: zeroing static unnecessary
0f12db5 2018-05-03 Daniel Agar - travis-ci enable coverity_scan
aceab8c 2018-05-05 Daniel Agar - Jenkins upload coverage to codecov.io
5780cd3 2018-05-05 Daniel Agar - Jenkins create PX4/Firmware test branch and push (#436)
cf957b5 2018-05-04 Daniel Agar - code coverage cmake and Jenkins support
4e0cd45 2018-05-03 Daniel Agar - doxygen cmake and Jenkins support