* change to use synchronize update vehicle state in pnc_map

* but print an error message for every 10 seconds, incase the user
really forget to provide prediction message

* script: record meta info into all bags.

* planning: add a gflag to protect nudge slowdown behavior.

* use the earliest time when user presses 'd'
* timestamp returned by rospy.Time.now() seems incorrect.

Localization: Add /apollo/localization/msf_gnss and /apollo/localization/msf_lidar topics in scripts/record_bag.sh. (#1929)

* planning: reduce traffic light stop distance to 0.2 m

* planning: reduce minimum follow distance to 2m

* tools: set the default

* Create Software_FAQ.md

* Create General_FAQs.md

* Rename Software_FAQ.md to Software_FAQs.md

* Create Hardware_FAQs.md

* Update General_FAQs.md

* Update Software_FAQs.md

* Update Software_FAQs.md

* Update Software_FAQs.md

* Create Calibration_FAQs.md

* Update Calibration_FAQs.md

* Delete FAQ0.md

* Delete FAQ0_cn.md

* Delete FAQ1.md

* Delete FAQ1_cn.md

* Delete FAQ2.md

* Delete FAQ2_cn.md

* Create how_to_install_ubuntu.md

* Update how_to_install_ubuntu.md

* Create how_to_install_apollo_kernel.md

* Update how_to_install_apollo_kernel.md

* Create Software_FAQ.md

* Create General_FAQs.md

* Rename Software_FAQ.md to Software_FAQs.md

* Create Hardware_FAQs.md

* Update General_FAQs.md

* Update Software_FAQs.md

* Update Software_FAQs.md

* Update Software_FAQs.md

* Create Calibration_FAQs.md

* Update Calibration_FAQs.md

* Delete FAQ0.md

* Delete FAQ0_cn.md

* Delete FAQ1.md

* Delete FAQ1_cn.md

* Delete FAQ2.md

* Delete FAQ2_cn.md

(1)  Planning: improved the speed planning consistency by estimating speed limits with current speed. (2) bug fix in drivers. (#1913)

* Planning: improved the speed planning consistency by estimating speed limits with current speed.

* Drivers and Perception: bug fix.

* Planning: consider close obstacles.

line swing.