Current webmock is not compatible w/ Ruby <2.0.

* Added support for AMap, aka AutoNavi Map, 高德地图

* Try to include amap error info if failed

* Get correct result from amap response

* Fix result error in amap return

* Refactor codes for AMap handling

* Refactor codes for amap result handling

* Refactor amap handling codes

* Fixed coordinates handling error

* Added tests

* Fixded amap result handling and tests

* Lock webmock on 2.3.2 for ruby 1.9.3 support

Use sqlite_ext 1.5.0 which has been broadened to work with Ruby
versions prior to 2.x, and remember to add it to files in the
./gemfiles/ directory for use with CI tests, not just to
Gemfile in the root directory.

Switch to byebug for MRI 2.x debugging.  Debugger is not supported for 2.1.2 and up, and was never fully 2.x compatible.

Fixes the problem described here:
https://github.com/mongoid/mongoid/issues/2579

This should be reverted when the Mongoid issue (or whatever it is)
is fixed.

Geocoder should be required after other things like Rails and Mongoid.

Also update contents of .gitignore from same.